Deprecate ChannelInboundHandlerAdapter and ChannelOutboundHandlerAdapter (#8929)

Motivation:

As we now us java8 as minimum java version we can deprecate ChannelInboundHandlerAdapter / ChannelOutboundHandlerAdapter and just move the default implementations into the interfaces. This makes things a bit more flexible for the end-user and also simplifies the class-hierarchy.

Modifications:

- Mark ChannelInboundHandlerAdapter and ChannelOutboundHandlerAdapter as deprecated
- Add default implementations to ChannelInboundHandler / ChannelOutboundHandler
- Refactor our code to not use ChannelInboundHandlerAdapter / ChannelOutboundHandlerAdapter anymore

Result:

Cleanup class-hierarchy and make things a bit more flexible.

codec-http/src/main/java/io/netty/handler/codec/http/HttpServerExpectContinueHandler.java

@@ -18,7 +18,7 @@ package io.netty.handler.codec.http;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.util.ReferenceCountUtil;
 
 import static io.netty.handler.codec.http.HttpHeaderNames.CONTENT_LENGTH;
@@ -44,7 +44,7 @@ import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
  *  </pre>
  * </blockquote>
  */
-public class HttpServerExpectContinueHandler extends ChannelInboundHandlerAdapter {
+public class HttpServerExpectContinueHandler implements ChannelInboundHandler {
 
     private static final FullHttpResponse EXPECTATION_FAILED = new DefaultFullHttpResponse(
             HTTP_1_1, HttpResponseStatus.EXPECTATION_FAILED, Unpooled.EMPTY_BUFFER);
@@ -92,6 +92,6 @@ public class HttpServerExpectContinueHandler extends ChannelInboundHandlerAdapte
                 req.headers().remove(HttpHeaderNames.EXPECT);
             }
         }
-        super.channelRead(ctx, msg);
+        ctx.fireChannelRead(msg);
     }
 }

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/Utf8FrameValidator.java

@@ -19,13 +19,13 @@ import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.handler.codec.CorruptedFrameException;
 
 /**
  *
  */
-public class Utf8FrameValidator extends ChannelInboundHandlerAdapter {
+public class Utf8FrameValidator implements ChannelInboundHandler {
 
     private int fragmentedFramesCount;
     private Utf8Validator utf8Validator;
@@ -74,7 +74,7 @@ public class Utf8FrameValidator extends ChannelInboundHandlerAdapter {
             }
         }
 
-        super.channelRead(ctx, msg);
+        ctx.fireChannelRead(msg);
     }
 
     private void checkUTF8String(ByteBuf buffer) {
@@ -89,6 +89,6 @@ public class Utf8FrameValidator extends ChannelInboundHandlerAdapter {
         if (cause instanceof CorruptedFrameException && ctx.channel().isOpen()) {
             ctx.writeAndFlush(Unpooled.EMPTY_BUFFER).addListener(ChannelFutureListener.CLOSE);
         }
-        super.exceptionCaught(ctx, cause);
+        ctx.fireExceptionCaught(cause);
     }
 }

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/WebSocketClientProtocolHandshakeHandler.java

@@ -15,13 +15,12 @@
  */
 package io.netty.handler.codec.http.websocketx;
 
-import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.handler.codec.http.FullHttpResponse;
 
-class WebSocketClientProtocolHandshakeHandler extends ChannelInboundHandlerAdapter {
+class WebSocketClientProtocolHandshakeHandler implements ChannelInboundHandler {
     private final WebSocketClientHandshaker handshaker;
 
     WebSocketClientProtocolHandshakeHandler(WebSocketClientHandshaker handshaker) {
@@ -30,7 +29,7 @@ class WebSocketClientProtocolHandshakeHandler extends ChannelInboundHandlerAdapt
 
     @Override
     public void channelActive(final ChannelHandlerContext ctx) throws Exception {
-        super.channelActive(ctx);
+        ctx.fireChannelActive();
         handshaker.handshake(ctx.channel()).addListener((ChannelFutureListener) future -> {
             if (!future.isSuccess()) {
                 ctx.fireExceptionCaught(future.cause());

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/WebSocketServerProtocolHandler.java

@@ -21,7 +21,6 @@ import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInboundHandler;
-import io.netty.channel.ChannelInboundHandlerAdapter;
 import io.netty.channel.ChannelPipeline;
 import io.netty.handler.codec.http.DefaultFullHttpResponse;
 import io.netty.handler.codec.http.FullHttpRequest;
@@ -199,7 +198,7 @@ public class WebSocketServerProtocolHandler extends WebSocketProtocolHandler {
     }
 
     static ChannelHandler forbiddenHttpRequestResponder() {
-        return new ChannelInboundHandlerAdapter() {
+        return new ChannelInboundHandler() {
             @Override
             public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
                 if (msg instanceof FullHttpRequest) {

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/WebSocketServerProtocolHandshakeHandler.java

@@ -18,7 +18,7 @@ package io.netty.handler.codec.http.websocketx;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelPipeline;
 import io.netty.handler.codec.http.DefaultFullHttpResponse;
 import io.netty.handler.codec.http.FullHttpRequest;
@@ -35,7 +35,7 @@ import static io.netty.handler.codec.http.HttpVersion.*;
 /**
  * Handles the HTTP handshake (the HTTP Upgrade request) for {@link WebSocketServerProtocolHandler}.
  */
-class WebSocketServerProtocolHandshakeHandler extends ChannelInboundHandlerAdapter {
+class WebSocketServerProtocolHandshakeHandler implements ChannelInboundHandler {
 
     private final String websocketPath;
     private final String subprotocols;

codec-http/src/test/java/io/netty/handler/codec/http/HttpClientUpgradeHandlerTest.java

@@ -16,7 +16,7 @@
 package io.netty.handler.codec.http;
 
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.embedded.EmbeddedChannel;
 
 import java.util.Collection;
@@ -58,7 +58,7 @@ public class HttpClientUpgradeHandlerTest {
         }
     }
 
-    private static final class UserEventCatcher extends ChannelInboundHandlerAdapter {
+    private static final class UserEventCatcher implements ChannelInboundHandler {
         private Object evt;
 
         public Object getUserEvent() {

codec-http/src/test/java/io/netty/handler/codec/http/HttpContentDecoderTest.java

@@ -19,7 +19,7 @@ package io.netty.handler.codec.http;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.handler.codec.CodecException;
 import io.netty.handler.codec.DecoderException;
@@ -274,7 +274,7 @@ public class HttpContentDecoderTest {
         final int maxBytes = 10;
         HttpObjectAggregator aggregator = new HttpObjectAggregator(maxBytes);
         final AtomicReference<FullHttpRequest> secondRequestRef = new AtomicReference<>();
-        EmbeddedChannel channel = new EmbeddedChannel(decoder, aggregator, new ChannelInboundHandlerAdapter() {
+        EmbeddedChannel channel = new EmbeddedChannel(decoder, aggregator, new ChannelInboundHandler() {
             @Override
             public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
                 if (msg instanceof FullHttpRequest) {
@@ -531,7 +531,7 @@ public class HttpContentDecoderTest {
         HttpContentDecoder decoder = new HttpContentDecoder() {
             @Override
             protected EmbeddedChannel newContentDecoder(String contentEncoding) throws Exception {
-                return new EmbeddedChannel(new ChannelInboundHandlerAdapter() {
+                return new EmbeddedChannel(new ChannelInboundHandler() {
                     @Override
                     public void channelInactive(ChannelHandlerContext ctx) throws Exception {
                         ctx.fireExceptionCaught(new DecoderException());
@@ -542,11 +542,11 @@ public class HttpContentDecoderTest {
         };
 
         final AtomicBoolean channelInactiveCalled = new AtomicBoolean();
-        EmbeddedChannel channel = new EmbeddedChannel(decoder, new ChannelInboundHandlerAdapter() {
+        EmbeddedChannel channel = new EmbeddedChannel(decoder, new ChannelInboundHandler() {
             @Override
             public void channelInactive(ChannelHandlerContext ctx) throws Exception {
                 assertTrue(channelInactiveCalled.compareAndSet(false, true));
-                super.channelInactive(ctx);
+                ctx.fireChannelInactive();
             }
         });
         assertTrue(channel.writeInbound(new DefaultHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, "/")));

codec-http/src/test/java/io/netty/handler/codec/http/HttpContentDecompressorTest.java

@@ -17,8 +17,9 @@ package io.netty.handler.codec.http;
 
 import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
-import io.netty.channel.ChannelOutboundHandlerAdapter;
+
+import io.netty.channel.ChannelOutboundHandler;
 import io.netty.channel.embedded.EmbeddedChannel;
 import org.junit.Assert;
 import org.junit.Test;
@@ -31,13 +32,13 @@ public class HttpContentDecompressorTest {
     @Test
     public void testInvokeReadWhenNotProduceMessage() {
         final AtomicInteger readCalled = new AtomicInteger();
-        EmbeddedChannel channel = new EmbeddedChannel(new ChannelOutboundHandlerAdapter() {
+        EmbeddedChannel channel = new EmbeddedChannel(new ChannelOutboundHandler() {
             @Override
             public void read(ChannelHandlerContext ctx) {
                 readCalled.incrementAndGet();
                 ctx.read();
             }
-        }, new HttpContentDecompressor(), new ChannelInboundHandlerAdapter() {
+        }, new HttpContentDecompressor(), new ChannelInboundHandler() {
             @Override
             public void channelRead(ChannelHandlerContext ctx, Object msg) {
                 ctx.fireChannelRead(msg);

codec-http/src/test/java/io/netty/handler/codec/http/HttpContentEncoderTest.java

@@ -19,7 +19,7 @@ package io.netty.handler.codec.http;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.handler.codec.CodecException;
 import io.netty.handler.codec.DecoderResult;
@@ -397,7 +397,7 @@ public class HttpContentEncoderTest {
             @Override
             protected Result beginEncode(HttpResponse headers, String acceptEncoding) throws Exception {
                 return new Result("myencoding", new EmbeddedChannel(
-                        new ChannelInboundHandlerAdapter() {
+                        new ChannelInboundHandler() {
                     @Override
                     public void channelInactive(ChannelHandlerContext ctx) throws Exception {
                         ctx.fireExceptionCaught(new EncoderException());
@@ -408,11 +408,11 @@ public class HttpContentEncoderTest {
         };
 
         final AtomicBoolean channelInactiveCalled = new AtomicBoolean();
-        EmbeddedChannel channel = new EmbeddedChannel(encoder, new ChannelInboundHandlerAdapter() {
+        EmbeddedChannel channel = new EmbeddedChannel(encoder, new ChannelInboundHandler() {
             @Override
             public void channelInactive(ChannelHandlerContext ctx) throws Exception {
                 assertTrue(channelInactiveCalled.compareAndSet(false, true));
-                super.channelInactive(ctx);
+                ctx.fireChannelInactive();
             }
         });
         assertTrue(channel.writeInbound(new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, "/")));

codec-http/src/test/java/io/netty/handler/codec/http/HttpServerUpgradeHandlerTest.java

@@ -18,16 +18,15 @@ package io.netty.handler.codec.http;
 import java.util.Collection;
 import java.util.Collections;
 
+import io.netty.channel.ChannelInboundHandler;
 import org.junit.Test;
 
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelDuplexHandler;
-import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
 import io.netty.channel.ChannelPromise;
 import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.handler.codec.http.HttpServerUpgradeHandler.UpgradeCodec;
@@ -57,7 +56,7 @@ public class HttpServerUpgradeHandlerTest {
             assertNotNull(ctx.pipeline().get(HttpServerUpgradeHandler.class));
 
             // Add a marker handler to signal that the upgrade has happened
-            ctx.pipeline().addAfter(ctx.name(), "marker", new ChannelInboundHandlerAdapter());
+            ctx.pipeline().addAfter(ctx.name(), "marker", new ChannelInboundHandler() { });
           }
     }
 

codec-http/src/test/java/io/netty/handler/codec/http/websocketx/WebSocketServerProtocolHandlerTest.java

@@ -17,8 +17,8 @@ package io.netty.handler.codec.http.websocketx;
 
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
-import io.netty.channel.ChannelOutboundHandlerAdapter;
+import io.netty.channel.ChannelOutboundHandler;
 import io.netty.channel.ChannelPromise;
 import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.handler.codec.http.DefaultFullHttpRequest;
@@ -154,7 +154,7 @@ public class WebSocketServerProtocolHandlerTest {
         return new String(response.content().array());
     }
 
-    private class MockOutboundHandler extends ChannelOutboundHandlerAdapter {
+    private class MockOutboundHandler implements ChannelOutboundHandler {
 
         @Override
         public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
@@ -167,7 +167,7 @@ public class WebSocketServerProtocolHandlerTest {
         }
     }
 
-    private static class CustomTextFrameHandler extends ChannelInboundHandlerAdapter {
+    private static class CustomTextFrameHandler implements ChannelInboundHandler {
         private String content;
 
         @Override

codec-http2/src/main/java/io/netty/handler/codec/http2/InboundHttpToHttp2Adapter.java

@@ -16,7 +16,7 @@
 package io.netty.handler.codec.http2;
 
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.handler.codec.http.FullHttpMessage;
 import io.netty.handler.codec.http.HttpHeaders;
 import io.netty.handler.codec.http.HttpScheme;
@@ -26,7 +26,7 @@ import io.netty.util.internal.UnstableApi;
  * Translates HTTP/1.x object reads into HTTP/2 frames.
  */
 @UnstableApi
-public class InboundHttpToHttp2Adapter extends ChannelInboundHandlerAdapter {
+public class InboundHttpToHttp2Adapter implements ChannelInboundHandler {
     private final Http2Connection connection;
     private final Http2FrameListener listener;
 
@@ -45,7 +45,7 @@ public class InboundHttpToHttp2Adapter extends ChannelInboundHandlerAdapter {
         if (msg instanceof FullHttpMessage) {
             handle(ctx, connection, listener, (FullHttpMessage) msg);
         } else {
-            super.channelRead(ctx, msg);
+            ctx.fireChannelRead(msg);
         }
     }
 

codec-http2/src/test/java/io/netty/handler/codec/http2/CleartextHttp2ServerUpgradeHandlerTest.java

@@ -19,7 +19,7 @@ import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.handler.codec.http.DefaultHttpHeaders;
@@ -27,7 +27,6 @@ import io.netty.handler.codec.http.HttpMethod;
 import io.netty.handler.codec.http.HttpRequest;
 import io.netty.handler.codec.http.HttpServerCodec;
 import io.netty.handler.codec.http.HttpServerUpgradeHandler;
-import io.netty.handler.codec.http.HttpServerUpgradeHandler.UpgradeCodec;
 import io.netty.handler.codec.http.HttpServerUpgradeHandler.UpgradeCodecFactory;
 import io.netty.handler.codec.http.HttpServerUpgradeHandler.UpgradeEvent;
 import io.netty.handler.codec.http.HttpVersion;
@@ -79,7 +78,7 @@ public class CleartextHttp2ServerUpgradeHandlerTest {
 
         CleartextHttp2ServerUpgradeHandler handler = new CleartextHttp2ServerUpgradeHandler(
                 httpServerCodec, upgradeHandler, http2ConnectionHandler);
-        channel = new EmbeddedChannel(handler, new ChannelInboundHandlerAdapter() {
+        channel = new EmbeddedChannel(handler, new ChannelInboundHandler() {
             @Override
             public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
                 userEvents.add(evt);
@@ -205,7 +204,7 @@ public class CleartextHttp2ServerUpgradeHandlerTest {
 
         CleartextHttp2ServerUpgradeHandler handler = new CleartextHttp2ServerUpgradeHandler(
                 httpServerCodec, upgradeHandler, http2Codec);
-        channel = new EmbeddedChannel(handler, new ChannelInboundHandlerAdapter() {
+        channel = new EmbeddedChannel(handler, new ChannelInboundHandler() {
             @Override
             public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
                 userEvents.add(evt);

codec-http2/src/test/java/io/netty/handler/codec/http2/DataCompressionHttp2Test.java

@@ -21,7 +21,7 @@ import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.ChannelPromise;
@@ -31,7 +31,6 @@ import io.netty.channel.socket.nio.NioServerSocketChannel;
 import io.netty.channel.socket.nio.NioSocketChannel;
 import io.netty.handler.codec.http.HttpHeaderNames;
 import io.netty.handler.codec.http.HttpHeaderValues;
-import io.netty.handler.codec.http2.Http2TestUtil.Http2Runnable;
 import io.netty.util.AsciiString;
 import io.netty.util.CharsetUtil;
 import io.netty.util.NetUtil;
@@ -41,8 +40,6 @@ import org.junit.Before;
 import org.junit.Test;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
-import org.mockito.invocation.InvocationOnMock;
-import org.mockito.stubbing.Answer;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
@@ -323,7 +320,7 @@ public class DataCompressionHttp2Test {
                         .gracefulShutdownTimeoutMillis(0)
                         .codec(decoder, clientEncoder).build();
                 p.addLast(clientHandler);
-                p.addLast(new ChannelInboundHandlerAdapter() {
+                p.addLast(new ChannelInboundHandler() {
                     public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
                         if (evt == Http2ConnectionPrefaceAndSettingsFrameWrittenEvent.INSTANCE) {
                             prefaceWrittenLatch.countDown();

codec-http2/src/test/java/io/netty/handler/codec/http2/Http2ClientUpgradeCodecTest.java

@@ -16,7 +16,7 @@ package io.netty.handler.codec.http2;
 
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.handler.codec.http.DefaultFullHttpRequest;
 import io.netty.handler.codec.http.FullHttpRequest;
@@ -44,13 +44,13 @@ public class Http2ClientUpgradeCodecTest {
     @Test
     public void testUpgradeToHttp2MultiplexCodec() throws Exception {
         testUpgrade(Http2MultiplexCodecBuilder.forClient(new HttpInboundHandler())
-            .withUpgradeStreamHandler(new ChannelInboundHandlerAdapter()).build());
+            .withUpgradeStreamHandler(new ChannelInboundHandler() { }).build());
     }
 
     private static void testUpgrade(Http2ConnectionHandler handler) throws Exception {
         FullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.OPTIONS, "*");
 
-        EmbeddedChannel channel = new EmbeddedChannel(new ChannelInboundHandlerAdapter());
+        EmbeddedChannel channel = new EmbeddedChannel(new ChannelInboundHandler() { });
         ChannelHandlerContext ctx = channel.pipeline().firstContext();
         Http2ClientUpgradeCodec codec = new Http2ClientUpgradeCodec("connectionHandler", handler);
         codec.setUpgradeHeaders(ctx, request);
@@ -64,5 +64,5 @@ public class Http2ClientUpgradeCodecTest {
     }
 
     @ChannelHandler.Sharable
-    private static final class HttpInboundHandler extends ChannelInboundHandlerAdapter { }
+    private static final class HttpInboundHandler implements ChannelInboundHandler { }
 }

codec-http2/src/test/java/io/netty/handler/codec/http2/Http2ConnectionRoundtripTest.java

@@ -25,9 +25,9 @@ import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerAdapter;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
-import io.netty.channel.ChannelOutboundHandlerAdapter;
+import io.netty.channel.ChannelOutboundHandler;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.ChannelPromise;
 import io.netty.channel.MultithreadEventLoopGroup;
@@ -36,7 +36,6 @@ import io.netty.channel.local.LocalChannel;
 import io.netty.channel.local.LocalHandler;
 import io.netty.channel.local.LocalServerChannel;
 import io.netty.handler.codec.http2.Http2TestUtil.FrameCountDown;
-import io.netty.handler.codec.http2.Http2TestUtil.Http2Runnable;
 import io.netty.util.AsciiString;
 import io.netty.util.IllegalReferenceCountException;
 import io.netty.util.ReferenceCountUtil;
@@ -643,7 +642,7 @@ public class Http2ConnectionRoundtripTest {
         runInChannel(clientChannel, () -> {
             http2Client.encoder().writeHeaders(ctx(), 3, EmptyHttp2Headers.INSTANCE, 0, (short) 16, false, 0, false,
                     newPromise());
-            clientChannel.pipeline().addFirst(new ChannelOutboundHandlerAdapter() {
+            clientChannel.pipeline().addFirst(new ChannelOutboundHandler() {
                 @Override
                 public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
                     ReferenceCountUtil.release(msg);
@@ -1062,7 +1061,7 @@ public class Http2ConnectionRoundtripTest {
                         .validateHeaders(false)
                         .gracefulShutdownTimeoutMillis(0)
                         .build());
-                p.addLast(new ChannelInboundHandlerAdapter() {
+                p.addLast(new ChannelInboundHandler() {
                     @Override
                     public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
                         if (evt == Http2ConnectionPrefaceAndSettingsFrameWrittenEvent.INSTANCE) {

codec-http2/src/test/java/io/netty/handler/codec/http2/Http2FrameCodecTest.java

@@ -19,7 +19,7 @@ import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelPromise;
 import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.handler.codec.UnsupportedMessageTypeException;
@@ -779,7 +779,7 @@ public class Http2FrameCodecTest {
 
     @Test
     public void upgradeWithoutFlowControlling() throws Exception {
-        channel.pipeline().addAfter(frameCodec.ctx.name(), null, new ChannelInboundHandlerAdapter() {
+        channel.pipeline().addAfter(frameCodec.ctx.name(), null, new ChannelInboundHandler() {
             @Override
             public void channelRead(final ChannelHandlerContext ctx, Object msg) throws Exception {
                 if (msg instanceof Http2DataFrame) {

codec-http2/src/test/java/io/netty/handler/codec/http2/Http2FrameInboundWriter.java

@@ -22,7 +22,7 @@ import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelOutboundHandlerAdapter;
+import io.netty.channel.ChannelOutboundHandler;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.ChannelProgressivePromise;
 import io.netty.channel.ChannelPromise;
@@ -106,8 +106,8 @@ final class Http2FrameInboundWriter {
         writer.writeFrame(ctx, frameType, streamId, flags, payload, ctx.newPromise()).syncUninterruptibly();
     }
 
-    private static final class WriteInboundChannelHandlerContext extends ChannelOutboundHandlerAdapter
+    private static final class WriteInboundChannelHandlerContext
-            implements ChannelHandlerContext {
+            implements ChannelHandlerContext, ChannelOutboundHandler {
         private final EmbeddedChannel channel;
 
         WriteInboundChannelHandlerContext(EmbeddedChannel channel) {

codec-http2/src/test/java/io/netty/handler/codec/http2/Http2MultiplexCodecBuilderTest.java

@@ -25,7 +25,7 @@ import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandler.Sharable;
 import io.netty.channel.ChannelHandlerAdapter;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.EventLoopGroup;
 import io.netty.channel.MultithreadEventLoopGroup;
@@ -81,25 +81,25 @@ public class Http2MultiplexCodecBuilderTest {
 
                             @Override
                             protected void initChannel(Channel ch) throws Exception {
-                                ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                                ch.pipeline().addLast(new ChannelInboundHandler() {
                                     private boolean writable;
 
                                     @Override
                                     public void channelActive(ChannelHandlerContext ctx) throws Exception {
                                         writable |= ctx.channel().isWritable();
-                                        super.channelActive(ctx);
+                                        ctx.fireChannelActive();
                                     }
 
                                     @Override
                                     public void channelWritabilityChanged(ChannelHandlerContext ctx) throws Exception {
                                         writable |= ctx.channel().isWritable();
-                                        super.channelWritabilityChanged(ctx);
+                                        ctx.fireChannelWritabilityChanged();
                                     }
 
                                     @Override
                                     public void channelInactive(ChannelHandlerContext ctx) throws Exception {
                                         assertTrue(writable);
-                                        super.channelInactive(ctx);
+                                        ctx.fireChannelInactive();
                                     }
                                 });
                                 ch.pipeline().addLast(serverLastInboundHandler);

codec-http2/src/test/java/io/netty/handler/codec/http2/Http2MultiplexCodecClientUpgradeTest.java

@@ -14,11 +14,11 @@
  */
 package io.netty.handler.codec.http2;
 
+import io.netty.channel.ChannelInboundHandler;
 import org.junit.Test;
 
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
 import io.netty.channel.embedded.EmbeddedChannel;
 
 import static org.junit.Assert.assertEquals;
@@ -28,14 +28,14 @@ import static org.junit.Assert.assertTrue;
 public class Http2MultiplexCodecClientUpgradeTest {
 
     @ChannelHandler.Sharable
-    private final class NoopHandler extends ChannelInboundHandlerAdapter {
+    private final class NoopHandler implements ChannelInboundHandler {
         @Override
         public void channelActive(ChannelHandlerContext ctx) {
             ctx.channel().close();
         }
     }
 
-    private final class UpgradeHandler extends ChannelInboundHandlerAdapter {
+    private final class UpgradeHandler implements ChannelInboundHandler {
         Http2Stream.State stateOnActive;
         int streamId;
 
@@ -44,7 +44,7 @@ public class Http2MultiplexCodecClientUpgradeTest {
             Http2StreamChannel ch = (Http2StreamChannel) ctx.channel();
             stateOnActive = ch.stream().state();
             streamId = ch.stream().id();
-            super.channelActive(ctx);
+            ctx.fireChannelActive();
         }
     }
 

codec-http2/src/test/java/io/netty/handler/codec/http2/Http2MultiplexCodecTest.java

@@ -21,7 +21,7 @@ import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelPromise;
 import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.handler.codec.http.HttpMethod;
@@ -33,7 +33,6 @@ import io.netty.util.AttributeKey;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
-import org.mockito.ArgumentMatcher;
 import org.mockito.Mockito;
 import org.mockito.invocation.InvocationOnMock;
 import org.mockito.stubbing.Answer;
@@ -133,7 +132,7 @@ public class Http2MultiplexCodecTest {
 
     @Test
     public void writeUnknownFrame() {
-        Http2StreamChannel childChannel = newOutboundStream(new ChannelInboundHandlerAdapter() {
+        Http2StreamChannel childChannel = newOutboundStream(new ChannelInboundHandler() {
             @Override
             public void channelActive(ChannelHandlerContext ctx) {
                 ctx.writeAndFlush(new DefaultHttp2HeadersFrame(new DefaultHttp2Headers()));
@@ -157,7 +156,7 @@ public class Http2MultiplexCodecTest {
                                                 AtomicInteger maxReads, final ChannelHandler childHandler) {
         final AtomicReference<Http2StreamChannel> streamChannelRef = new AtomicReference<>();
         childChannelInitializer.maxReads = maxReads;
-        childChannelInitializer.handler = new ChannelInboundHandlerAdapter() {
+        childChannelInitializer.handler = new ChannelInboundHandler() {
             @Override
             public void channelRegistered(ChannelHandlerContext ctx) {
                 assertNull(streamChannelRef.get());
@@ -184,7 +183,7 @@ public class Http2MultiplexCodecTest {
         // header frame and unknown frame
         verifyFramesMultiplexedToCorrectChannel(channel, handler, 2);
 
-        Channel childChannel = newOutboundStream(new ChannelInboundHandlerAdapter());
+        Channel childChannel = newOutboundStream(new ChannelInboundHandler() { });
         assertTrue(childChannel.isActive());
     }
 
@@ -310,7 +309,7 @@ public class Http2MultiplexCodecTest {
         assertNotNull(headersFrame);
 
         // Add a handler which will request reads.
-        childChannel.pipeline().addFirst(new ChannelInboundHandlerAdapter() {
+        childChannel.pipeline().addFirst(new ChannelInboundHandler() {
             @Override
             public void channelRead(ChannelHandlerContext ctx, Object msg) {
                 ctx.fireChannelRead(msg);
@@ -364,7 +363,7 @@ public class Http2MultiplexCodecTest {
 
     @Test
     public void outboundStreamShouldWriteResetFrameOnClose_headersSent() {
-        ChannelHandler handler = new ChannelInboundHandlerAdapter() {
+        ChannelHandler handler = new ChannelInboundHandler() {
             @Override
             public void channelActive(ChannelHandlerContext ctx) {
                 ctx.writeAndFlush(new DefaultHttp2HeadersFrame(new DefaultHttp2Headers()));
@@ -399,7 +398,7 @@ public class Http2MultiplexCodecTest {
             }
         });
 
-        Http2StreamChannel childChannel = newOutboundStream(new ChannelInboundHandlerAdapter() {
+        Http2StreamChannel childChannel = newOutboundStream(new ChannelInboundHandler() {
             @Override
             public void channelActive(ChannelHandlerContext ctx) {
                 ctx.writeAndFlush(new DefaultHttp2HeadersFrame(new DefaultHttp2Headers()));
@@ -630,7 +629,7 @@ public class Http2MultiplexCodecTest {
     public void settingChannelOptsAndAttrs() {
         AttributeKey<String> key = AttributeKey.newInstance("foo");
 
-        Channel childChannel = newOutboundStream(new ChannelInboundHandlerAdapter());
+        Channel childChannel = newOutboundStream(new ChannelInboundHandler() { });
         childChannel.config().setAutoRead(false).setWriteSpinCount(1000);
         childChannel.attr(key).set("bar");
         assertFalse(childChannel.config().isAutoRead());
@@ -640,7 +639,7 @@ public class Http2MultiplexCodecTest {
 
     @Test
     public void outboundFlowControlWritability() {
-        Http2StreamChannel childChannel = newOutboundStream(new ChannelInboundHandlerAdapter());
+        Http2StreamChannel childChannel = newOutboundStream(new ChannelInboundHandler() { });
         assertTrue(childChannel.isActive());
 
         assertTrue(childChannel.isWritable());
@@ -692,13 +691,13 @@ public class Http2MultiplexCodecTest {
         assertTrue(childChannel.isOpen());
         assertTrue(childChannel.isActive());
 
-        childChannel.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+        childChannel.pipeline().addLast(new ChannelInboundHandler() {
             @Override
             public void channelInactive(ChannelHandlerContext ctx) throws Exception {
                 channelOpen.set(ctx.channel().isOpen());
                 channelActive.set(ctx.channel().isActive());
 
-                super.channelInactive(ctx);
+                ctx.fireChannelInactive();
             }
         });
 
@@ -713,7 +712,7 @@ public class Http2MultiplexCodecTest {
         final AtomicInteger exceptionCaught = new AtomicInteger(-1);
         final AtomicInteger channelInactive = new AtomicInteger(-1);
         final AtomicInteger channelUnregistered = new AtomicInteger(-1);
-        Http2StreamChannel childChannel = newOutboundStream(new ChannelInboundHandlerAdapter() {
+        Http2StreamChannel childChannel = newOutboundStream(new ChannelInboundHandler() {
 
             @Override
             public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
@@ -722,24 +721,24 @@ public class Http2MultiplexCodecTest {
             }
         });
 
-        childChannel.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+        childChannel.pipeline().addLast(new ChannelInboundHandler() {
 
             @Override
             public void channelInactive(ChannelHandlerContext ctx) throws Exception {
                 channelInactive.set(count.getAndIncrement());
-                super.channelInactive(ctx);
+                ctx.fireChannelInactive();
             }
 
             @Override
             public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
                 exceptionCaught.set(count.getAndIncrement());
-                super.exceptionCaught(ctx, cause);
+                ctx.fireExceptionCaught(cause);
             }
 
             @Override
             public void channelUnregistered(ChannelHandlerContext ctx) throws Exception {
                 channelUnregistered.set(count.getAndIncrement());
-                super.channelUnregistered(ctx);
+                ctx.fireChannelUnregistered();
             }
         });
 
@@ -785,7 +784,7 @@ public class Http2MultiplexCodecTest {
 
         assertEquals(new DefaultHttp2HeadersFrame(request).stream(childChannel.stream()), inboundHandler.readInbound());
 
-        ChannelHandler readCompleteSupressHandler = new ChannelInboundHandlerAdapter() {
+        ChannelHandler readCompleteSupressHandler = new ChannelInboundHandler() {
             @Override
             public void channelReadComplete(ChannelHandlerContext ctx) {
                 // We want to simulate the parent channel calling channelRead and delay calling channelReadComplete.
@@ -848,7 +847,7 @@ public class Http2MultiplexCodecTest {
 
         assertEquals(new DefaultHttp2HeadersFrame(request).stream(childChannel.stream()), inboundHandler.readInbound());
 
-        ChannelHandler readCompleteSupressHandler = new ChannelInboundHandlerAdapter() {
+        ChannelHandler readCompleteSupressHandler = new ChannelInboundHandler() {
             @Override
             public void channelReadComplete(ChannelHandlerContext ctx) {
                 // We want to simulate the parent channel calling channelRead and delay calling channelReadComplete.
@@ -908,7 +907,7 @@ public class Http2MultiplexCodecTest {
 
         assertEquals(new DefaultHttp2HeadersFrame(request).stream(childChannel.stream()), inboundHandler.readInbound());
 
-        ChannelHandler readCompleteSupressHandler = new ChannelInboundHandlerAdapter() {
+        ChannelHandler readCompleteSupressHandler = new ChannelInboundHandler() {
             @Override
             public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
                 // We want to simulate the parent channel calling channelRead and delay calling channelReadComplete.

codec-http2/src/test/java/io/netty/handler/codec/http2/Http2ServerUpgradeCodecTest.java

@@ -17,7 +17,7 @@ package io.netty.handler.codec.http2;
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.handler.codec.http.DefaultFullHttpRequest;
 import io.netty.handler.codec.http.DefaultHttpHeaders;
@@ -57,7 +57,7 @@ public class Http2ServerUpgradeCodecTest {
         request.headers().set(HttpHeaderNames.UPGRADE, "h2c");
         request.headers().set("HTTP2-Settings", "AAMAAABkAAQAAP__");
 
-        EmbeddedChannel channel = new EmbeddedChannel(new ChannelInboundHandlerAdapter());
+        EmbeddedChannel channel = new EmbeddedChannel(new ChannelInboundHandler() { });
         ChannelHandlerContext ctx = channel.pipeline().firstContext();
         Http2ServerUpgradeCodec codec = new Http2ServerUpgradeCodec("connectionHandler", handler);
         assertTrue(codec.prepareUpgradeResponse(ctx, request, new DefaultHttpHeaders()));
@@ -78,5 +78,5 @@ public class Http2ServerUpgradeCodecTest {
     }
 
     @ChannelHandler.Sharable
-    private static final class HttpInboundHandler extends ChannelInboundHandlerAdapter { }
+    private static final class HttpInboundHandler implements ChannelInboundHandler { }
 }

codec-http2/src/test/java/io/netty/handler/codec/http2/Http2StreamFrameToHttpObjectCodecTest.java

@@ -21,7 +21,7 @@ import io.netty.buffer.ByteBufAllocator;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelOutboundHandlerAdapter;
+import io.netty.channel.ChannelOutboundHandler;
 import io.netty.channel.ChannelPromise;
 import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.handler.codec.EncoderException;
@@ -450,7 +450,7 @@ public class Http2StreamFrameToHttpObjectCodecTest {
 
         final SslContext ctx = SslContextBuilder.forClient().sslProvider(SslProvider.JDK).build();
         EmbeddedChannel ch = new EmbeddedChannel(ctx.newHandler(ByteBufAllocator.DEFAULT),
-                new ChannelOutboundHandlerAdapter() {
+                new ChannelOutboundHandler() {
                     @Override
                     public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
                         if (msg instanceof Http2StreamFrame) {
@@ -880,7 +880,7 @@ public class Http2StreamFrameToHttpObjectCodecTest {
 
         final SslContext ctx = SslContextBuilder.forClient().sslProvider(SslProvider.JDK).build();
         EmbeddedChannel tlsCh = new EmbeddedChannel(ctx.newHandler(ByteBufAllocator.DEFAULT),
-            new ChannelOutboundHandlerAdapter() {
+            new ChannelOutboundHandler() {
                 @Override
                 public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) {
                     if (msg instanceof Http2StreamFrame) {
@@ -893,7 +893,7 @@ public class Http2StreamFrameToHttpObjectCodecTest {
             }, sharedHandler);
 
         EmbeddedChannel plaintextCh = new EmbeddedChannel(
-            new ChannelOutboundHandlerAdapter() {
+            new ChannelOutboundHandler() {
                 @Override
                 public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) {
                     if (msg instanceof Http2StreamFrame) {

codec-http2/src/test/java/io/netty/handler/codec/http2/HttpToHttp2ConnectionHandlerTest.java

@@ -21,7 +21,7 @@ import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.ChannelPromise;
@@ -529,7 +529,7 @@ public class HttpToHttp2ConnectionHandlerTest {
                         .gracefulShutdownTimeoutMillis(0)
                         .build();
                 p.addLast(handler);
-                p.addLast(new ChannelInboundHandlerAdapter() {
+                p.addLast(new ChannelInboundHandler() {
                     @Override
                     public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
                         if (evt == Http2ConnectionPrefaceAndSettingsFrameWrittenEvent.INSTANCE) {

codec-http2/src/test/java/io/netty/handler/codec/http2/InboundHttp2ToHttpAdapterTest.java

@@ -21,7 +21,7 @@ import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.ChannelPromise;
@@ -665,7 +665,7 @@ public class InboundHttp2ToHttpAdapterTest {
 
                 clientDelegator = new HttpResponseDelegator(clientListener, clientLatch, clientLatch2);
                 p.addLast(clientDelegator);
-                p.addLast(new ChannelInboundHandlerAdapter() {
+                p.addLast(new ChannelInboundHandler() {
                     @Override
                     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
                         Http2Exception e = getEmbeddedHttp2Exception(cause);
@@ -673,11 +673,11 @@ public class InboundHttp2ToHttpAdapterTest {
                             clientException = e;
                             clientLatch.countDown();
                         } else {
-                            super.exceptionCaught(ctx, cause);
+                            ctx.fireExceptionCaught(cause);
                         }
                     }
                 });
-                p.addLast(new ChannelInboundHandlerAdapter() {
+                p.addLast(new ChannelInboundHandler() {
                     public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
                         if (evt == Http2ConnectionPrefaceAndSettingsFrameWrittenEvent.INSTANCE) {
                             prefaceWrittenLatch.countDown();

codec/src/main/java/io/netty/handler/codec/ByteToMessageDecoder.java

@@ -22,15 +22,16 @@ import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufAllocator;
 import io.netty.buffer.CompositeByteBuf;
 import io.netty.buffer.Unpooled;
+import io.netty.channel.ChannelHandlerAdapter;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.socket.ChannelInputShutdownEvent;
 import io.netty.util.internal.StringUtil;
 
 import java.util.List;
 
 /**
- * {@link ChannelInboundHandlerAdapter} which decodes bytes in a stream-like fashion from one {@link ByteBuf} to an
+ * {@link ChannelInboundHandler} which decodes bytes in a stream-like fashion from one {@link ByteBuf} to an
  * other Message type.
  *
  * For example here is an implementation which reads all readable bytes from
@@ -70,7 +71,7 @@ import java.util.List;
  * is not released or added to the <tt>out</tt> {@link List}. Use derived buffers like {@link ByteBuf#readSlice(int)}
  * to avoid leaking memory.
  */
-public abstract class ByteToMessageDecoder extends ChannelInboundHandlerAdapter {
+public abstract class ByteToMessageDecoder extends ChannelHandlerAdapter implements ChannelInboundHandler {
 
     /**
      * Cumulate {@link ByteBuf}s by merge them into one {@link ByteBuf}'s, using memory copies.
@@ -356,7 +357,7 @@ public abstract class ByteToMessageDecoder extends ChannelInboundHandlerAdapter
             // when the input has been shutdown.
             channelInputClosed(ctx, false);
         }
-        super.userEventTriggered(ctx, evt);
+        ctx.fireUserEventTriggered(evt);
     }
 
     private void channelInputClosed(ChannelHandlerContext ctx, boolean callChannelInactive) throws Exception {

codec/src/main/java/io/netty/handler/codec/MessageToByteEncoder.java

@@ -17,9 +17,9 @@ package io.netty.handler.codec;
 
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
+import io.netty.channel.ChannelHandlerAdapter;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelOutboundHandler;
-import io.netty.channel.ChannelOutboundHandlerAdapter;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.ChannelPromise;
 import io.netty.util.ReferenceCountUtil;
@@ -27,7 +27,7 @@ import io.netty.util.internal.TypeParameterMatcher;
 
 
 /**
- * {@link ChannelOutboundHandlerAdapter} which encodes message in a stream-like fashion from one message to an
+ * {@link ChannelOutboundHandler} which encodes message in a stream-like fashion from one message to an
  * {@link ByteBuf}.
  *
  *
@@ -43,7 +43,7 @@ import io.netty.util.internal.TypeParameterMatcher;
  *     }
  * </pre>
  */
-public abstract class MessageToByteEncoder<I> extends ChannelOutboundHandlerAdapter {
+public abstract class MessageToByteEncoder<I> extends ChannelHandlerAdapter implements ChannelOutboundHandler {
 
     private final TypeParameterMatcher matcher;
     private final boolean preferDirect;

codec/src/main/java/io/netty/handler/codec/MessageToMessageDecoder.java

@@ -15,9 +15,9 @@
  */
 package io.netty.handler.codec;
 
+import io.netty.channel.ChannelHandlerAdapter;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInboundHandler;
-import io.netty.channel.ChannelInboundHandlerAdapter;
 import io.netty.channel.ChannelPipeline;
 import io.netty.util.ReferenceCountUtil;
 import io.netty.util.ReferenceCounted;
@@ -26,7 +26,7 @@ import io.netty.util.internal.TypeParameterMatcher;
 import java.util.List;
 
 /**
- * {@link ChannelInboundHandlerAdapter} which decodes from one message to an other message.
+ * {@link ChannelInboundHandler} which decodes from one message to an other message.
  *
  *
  * For example here is an implementation which decodes a {@link String} to an {@link Integer} which represent
@@ -49,7 +49,7 @@ import java.util.List;
  * {@link ReferenceCounted#release()} on decoded messages.
  *
  */
-public abstract class MessageToMessageDecoder<I> extends ChannelInboundHandlerAdapter {
+public abstract class MessageToMessageDecoder<I> extends ChannelHandlerAdapter implements ChannelInboundHandler {
 
     private final TypeParameterMatcher matcher;
 

codec/src/main/java/io/netty/handler/codec/MessageToMessageEncoder.java

@@ -15,9 +15,9 @@
  */
 package io.netty.handler.codec;
 
+import io.netty.channel.ChannelHandlerAdapter;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelOutboundHandler;
-import io.netty.channel.ChannelOutboundHandlerAdapter;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.ChannelPromise;
 import io.netty.util.ReferenceCountUtil;
@@ -29,7 +29,7 @@ import io.netty.util.internal.TypeParameterMatcher;
 import java.util.List;
 
 /**
- * {@link ChannelOutboundHandlerAdapter} which encodes from one message to an other message
+ * {@link ChannelOutboundHandler} which encodes from one message to an other message
  *
  * For example here is an implementation which decodes an {@link Integer} to an {@link String}.
  *
@@ -49,7 +49,7 @@ import java.util.List;
  * are of type {@link ReferenceCounted}. This is needed as the {@link MessageToMessageEncoder} will call
  * {@link ReferenceCounted#release()} on encoded messages.
  */
-public abstract class MessageToMessageEncoder<I> extends ChannelOutboundHandlerAdapter {
+public abstract class MessageToMessageEncoder<I> extends ChannelHandlerAdapter implements ChannelOutboundHandler {
 
     private final TypeParameterMatcher matcher;
 

codec/src/test/java/io/netty/handler/codec/ByteToMessageDecoderTest.java

@@ -21,7 +21,7 @@ import io.netty.buffer.Unpooled;
 import io.netty.buffer.UnpooledByteBufAllocator;
 import io.netty.buffer.UnpooledHeapByteBuf;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.embedded.EmbeddedChannel;
 import org.junit.Test;
 
@@ -174,7 +174,7 @@ public class ByteToMessageDecoderTest {
                 assertFalse(in.isReadable());
                 out.add("data");
             }
-        }, new ChannelInboundHandlerAdapter() {
+        }, new ChannelInboundHandler() {
             @Override
             public void channelInactive(ChannelHandlerContext ctx) {
                 queue.add(3);
@@ -212,7 +212,7 @@ public class ByteToMessageDecoderTest {
             }
         };
 
-        EmbeddedChannel channel = new EmbeddedChannel(decoder, new ChannelInboundHandlerAdapter() {
+        EmbeddedChannel channel = new EmbeddedChannel(decoder, new ChannelInboundHandler() {
             @Override
             public void channelRead(ChannelHandlerContext ctx, Object msg) {
                 if (msg == upgradeMessage) {

codec/src/test/java/io/netty/handler/codec/MessageAggregatorTest.java

@@ -16,6 +16,7 @@
 
 package io.netty.handler.codec;
 
+import io.netty.channel.ChannelOutboundHandler;
 import org.junit.Test;
 
 import static org.junit.Assert.*;
@@ -26,12 +27,11 @@ import io.netty.buffer.ByteBufHolder;
 import io.netty.buffer.DefaultByteBufHolder;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelOutboundHandlerAdapter;
 import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.util.CharsetUtil;
 
 public class MessageAggregatorTest {
-    private static final class ReadCounter extends ChannelOutboundHandlerAdapter {
+    private static final class ReadCounter implements ChannelOutboundHandler {
         int value;
 
         @Override

codec/src/test/java/io/netty/handler/codec/MessageToMessageEncoderTest.java

@@ -18,7 +18,7 @@ package io.netty.handler.codec;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelOutboundHandlerAdapter;
+import io.netty.channel.ChannelOutboundHandler;
 import io.netty.channel.ChannelPromise;
 import io.netty.channel.embedded.EmbeddedChannel;
 import org.junit.Test;
@@ -55,7 +55,7 @@ public class MessageToMessageEncoderTest {
 
         final Exception firstWriteException = new Exception();
 
-        ChannelHandler writeThrower = new ChannelOutboundHandlerAdapter() {
+        ChannelHandler writeThrower = new ChannelOutboundHandler() {
             private boolean firstWritten;
             @Override
             public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) {

codec/src/test/java/io/netty/handler/codec/ReplayingDecoderTest.java

@@ -18,7 +18,7 @@ package io.netty.handler.codec;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.channel.socket.ChannelInputShutdownEvent;
 import org.junit.Test;
@@ -96,7 +96,7 @@ public class ReplayingDecoderTest {
         assertNull(ch.readInbound());
     }
 
-    private static final class BloatedLineDecoder extends ChannelInboundHandlerAdapter {
+    private static final class BloatedLineDecoder implements ChannelInboundHandler {
         @Override
         public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
             ctx.pipeline().replace(this, "less-bloated", new LineDecoder());
@@ -226,7 +226,7 @@ public class ReplayingDecoderTest {
                 assertFalse(in.isReadable());
                 out.add("data");
             }
-        }, new ChannelInboundHandlerAdapter() {
+        }, new ChannelInboundHandler() {
             @Override
             public void channelInactive(ChannelHandlerContext ctx) throws Exception {
                 queue.add(3);

example/src/main/java/io/netty/example/echo/EchoClientHandler.java

@@ -18,14 +18,14 @@ package io.netty.example.echo;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 
 /**
  * Handler implementation for the echo client.  It initiates the ping-pong
  * traffic between the echo client and server by sending the first message to
  * the server.
  */
-public class EchoClientHandler extends ChannelInboundHandlerAdapter {
+public class EchoClientHandler implements ChannelInboundHandler {
 
     private final ByteBuf firstMessage;
 

example/src/main/java/io/netty/example/echo/EchoServerHandler.java

@@ -17,13 +17,13 @@ package io.netty.example.echo;
 
 import io.netty.channel.ChannelHandler.Sharable;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 
 /**
  * Handler implementation for the echo server.
  */
 @Sharable
-public class EchoServerHandler extends ChannelInboundHandlerAdapter {
+public class EchoServerHandler implements ChannelInboundHandler {
 
     @Override
     public void channelRead(ChannelHandlerContext ctx, Object msg) {

example/src/main/java/io/netty/example/http2/helloworld/client/Http2ClientInitializer.java

@@ -15,7 +15,7 @@
 package io.netty.example.http2.helloworld.client;
 
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.socket.SocketChannel;
@@ -129,7 +129,7 @@ public class Http2ClientInitializer extends ChannelInitializer<SocketChannel> {
     /**
      * A handler that triggers the cleartext upgrade to HTTP/2 by sending an initial HTTP request.
      */
-    private final class UpgradeRequestHandler extends ChannelInboundHandlerAdapter {
+    private final class UpgradeRequestHandler implements ChannelInboundHandler {
         @Override
         public void channelActive(ChannelHandlerContext ctx) throws Exception {
             DefaultFullHttpRequest upgradeRequest =
@@ -148,7 +148,7 @@ public class Http2ClientInitializer extends ChannelInitializer<SocketChannel> {
     /**
      * Class that logs any User Events triggered on this channel.
      */
-    private static class UserEventLogger extends ChannelInboundHandlerAdapter {
+    private static class UserEventLogger implements ChannelInboundHandler {
         @Override
         public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
             System.out.println("User Event Triggered: " + evt);

example/src/main/java/io/netty/example/http2/helloworld/frame/server/Http2ServerInitializer.java

@@ -17,7 +17,7 @@
 package io.netty.example.http2.helloworld.frame.server;
 
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.SimpleChannelInboundHandler;
@@ -27,7 +27,6 @@ import io.netty.handler.codec.http.HttpMessage;
 import io.netty.handler.codec.http.HttpObjectAggregator;
 import io.netty.handler.codec.http.HttpServerCodec;
 import io.netty.handler.codec.http.HttpServerUpgradeHandler;
-import io.netty.handler.codec.http.HttpServerUpgradeHandler.UpgradeCodec;
 import io.netty.handler.codec.http.HttpServerUpgradeHandler.UpgradeCodecFactory;
 import io.netty.handler.codec.http2.Http2CodecUtil;
 import io.netty.handler.codec.http2.Http2FrameCodecBuilder;
@@ -110,7 +109,7 @@ public class Http2ServerInitializer extends ChannelInitializer<SocketChannel> {
     /**
      * Class that logs any User Events triggered on this channel.
      */
-    private static class UserEventLogger extends ChannelInboundHandlerAdapter {
+    private static class UserEventLogger implements ChannelInboundHandler {
         @Override
         public void userEventTriggered(ChannelHandlerContext ctx, Object evt) {
             System.out.println("User Event Triggered: " + evt);

example/src/main/java/io/netty/example/http2/helloworld/multiplex/server/Http2ServerInitializer.java

@@ -17,7 +17,7 @@
 package io.netty.example.http2.helloworld.multiplex.server;
 
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.SimpleChannelInboundHandler;
@@ -27,7 +27,6 @@ import io.netty.handler.codec.http.HttpMessage;
 import io.netty.handler.codec.http.HttpObjectAggregator;
 import io.netty.handler.codec.http.HttpServerCodec;
 import io.netty.handler.codec.http.HttpServerUpgradeHandler;
-import io.netty.handler.codec.http.HttpServerUpgradeHandler.UpgradeCodec;
 import io.netty.handler.codec.http.HttpServerUpgradeHandler.UpgradeCodecFactory;
 import io.netty.handler.codec.http2.Http2MultiplexCodecBuilder;
 import io.netty.handler.codec.http2.Http2CodecUtil;
@@ -110,7 +109,7 @@ public class Http2ServerInitializer extends ChannelInitializer<SocketChannel> {
     /**
      * Class that logs any User Events triggered on this channel.
      */
-    private static class UserEventLogger extends ChannelInboundHandlerAdapter {
+    private static class UserEventLogger implements ChannelInboundHandler {
         @Override
         public void userEventTriggered(ChannelHandlerContext ctx, Object evt) {
             System.out.println("User Event Triggered: " + evt);

example/src/main/java/io/netty/example/http2/helloworld/server/Http2ServerInitializer.java

@@ -17,7 +17,7 @@
 package io.netty.example.http2.helloworld.server;
 
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.SimpleChannelInboundHandler;
@@ -26,7 +26,6 @@ import io.netty.handler.codec.http.HttpMessage;
 import io.netty.handler.codec.http.HttpObjectAggregator;
 import io.netty.handler.codec.http.HttpServerCodec;
 import io.netty.handler.codec.http.HttpServerUpgradeHandler;
-import io.netty.handler.codec.http.HttpServerUpgradeHandler.UpgradeCodec;
 import io.netty.handler.codec.http.HttpServerUpgradeHandler.UpgradeCodecFactory;
 import io.netty.handler.codec.http2.CleartextHttp2ServerUpgradeHandler;
 import io.netty.handler.codec.http2.Http2CodecUtil;
@@ -111,7 +110,7 @@ public class Http2ServerInitializer extends ChannelInitializer<SocketChannel> {
     /**
      * Class that logs any User Events triggered on this channel.
      */
-    private static class UserEventLogger extends ChannelInboundHandlerAdapter {
+    private static class UserEventLogger implements ChannelInboundHandler {
         @Override
         public void userEventTriggered(ChannelHandlerContext ctx, Object evt) {
             System.out.println("User Event Triggered: " + evt);

example/src/main/java/io/netty/example/localecho/LocalEchoServerHandler.java

@@ -16,9 +16,9 @@
 package io.netty.example.localecho;
 
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 
-public class LocalEchoServerHandler extends ChannelInboundHandlerAdapter {
+public class LocalEchoServerHandler implements ChannelInboundHandler {
 
     @Override
     public void channelRead(ChannelHandlerContext ctx, Object msg) {

example/src/main/java/io/netty/example/objectecho/ObjectEchoClientHandler.java

@@ -16,7 +16,7 @@
 package io.netty.example.objectecho;
 
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -26,7 +26,7 @@ import java.util.List;
  * ping-pong traffic between the object echo client and server by sending the
  * first message to the server.
  */
-public class ObjectEchoClientHandler extends ChannelInboundHandlerAdapter {
+public class ObjectEchoClientHandler implements ChannelInboundHandler {
 
     private final List<Integer> firstMessage;
 

example/src/main/java/io/netty/example/objectecho/ObjectEchoServerHandler.java

@@ -16,13 +16,13 @@
 package io.netty.example.objectecho;
 
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 
 /**
  * Handles both client-side and server-side handler depending on which
  * constructor was called.
  */
-public class ObjectEchoServerHandler extends ChannelInboundHandlerAdapter {
+public class ObjectEchoServerHandler implements ChannelInboundHandler {
 
     @Override
     public void channelRead(ChannelHandlerContext ctx, Object msg) {

example/src/main/java/io/netty/example/ocsp/OcspClientExample.java

@@ -21,6 +21,7 @@ import java.math.BigInteger;
 import javax.net.ssl.SSLSession;
 import javax.security.cert.X509Certificate;
 
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.MultithreadEventLoopGroup;
 import io.netty.channel.nio.NioHandler;
 import org.bouncycastle.asn1.ocsp.OCSPResponseStatus;
@@ -33,7 +34,6 @@ import io.netty.bootstrap.Bootstrap;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.ChannelPipeline;
@@ -152,7 +152,7 @@ public class OcspClientExample {
         };
     }
 
-    private static class HttpClientHandler extends ChannelInboundHandlerAdapter {
+    private static class HttpClientHandler implements ChannelInboundHandler {
 
         private final String host;
 

example/src/main/java/io/netty/example/proxy/HexDumpProxyBackendHandler.java

@@ -16,12 +16,11 @@
 package io.netty.example.proxy;
 
 import io.netty.channel.Channel;
-import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 
-public class HexDumpProxyBackendHandler extends ChannelInboundHandlerAdapter {
+public class HexDumpProxyBackendHandler implements ChannelInboundHandler {
 
     private final Channel inboundChannel;
 

example/src/main/java/io/netty/example/proxy/HexDumpProxyFrontendHandler.java

@@ -21,10 +21,10 @@ import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelOption;
 
-public class HexDumpProxyFrontendHandler extends ChannelInboundHandlerAdapter {
+public class HexDumpProxyFrontendHandler implements ChannelInboundHandler {
 
     private final String remoteHost;
     private final int remotePort;

example/src/main/java/io/netty/example/sctp/SctpEchoClientHandler.java

@@ -18,7 +18,7 @@ package io.netty.example.sctp;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.sctp.SctpMessage;
 
 /**
@@ -26,7 +26,7 @@ import io.netty.channel.sctp.SctpMessage;
  * traffic between the echo client and server by sending the first message to
  * the server.
  */
-public class SctpEchoClientHandler extends ChannelInboundHandlerAdapter {
+public class SctpEchoClientHandler implements ChannelInboundHandler {
 
     private final ByteBuf firstMessage;
 

example/src/main/java/io/netty/example/sctp/SctpEchoServerHandler.java

@@ -17,13 +17,13 @@ package io.netty.example.sctp;
 
 import io.netty.channel.ChannelHandler.Sharable;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 
 /**
  * Handler implementation for the SCTP echo server.
  */
 @Sharable
-public class SctpEchoServerHandler extends ChannelInboundHandlerAdapter {
+public class SctpEchoServerHandler implements ChannelInboundHandler {
 
     @Override
     public void channelRead(ChannelHandlerContext ctx, Object msg) {

example/src/main/java/io/netty/example/socksproxy/DirectClientHandler.java

@@ -17,10 +17,10 @@ package io.netty.example.socksproxy;
 
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.util.concurrent.Promise;
 
-public final class DirectClientHandler extends ChannelInboundHandlerAdapter {
+public final class DirectClientHandler implements ChannelInboundHandler {
 
     private final Promise<Channel> promise;
 

example/src/main/java/io/netty/example/socksproxy/RelayHandler.java

@@ -18,10 +18,10 @@ package io.netty.example.socksproxy;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.util.ReferenceCountUtil;
 
-public final class RelayHandler extends ChannelInboundHandlerAdapter {
+public final class RelayHandler implements ChannelInboundHandler {
 
     private final Channel relayChannel;
 

handler-proxy/src/test/java/io/netty/handler/proxy/HttpProxyHandlerTest.java

@@ -20,7 +20,7 @@ import io.netty.bootstrap.ServerBootstrap;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelPromise;
 import io.netty.channel.EventLoopGroup;
@@ -186,7 +186,7 @@ public class HttpProxyHandlerTest {
                         @Override
                         protected void initChannel(Channel ch) {
                             ch.pipeline().addFirst(new HttpResponseEncoder());
-                            ch.pipeline().addFirst(new ChannelInboundHandlerAdapter() {
+                            ch.pipeline().addFirst(new ChannelInboundHandler() {
                                 @Override
                                 public void channelActive(ChannelHandlerContext ctx) {
                                     DefaultFullHttpResponse response = new DefaultFullHttpResponse(
@@ -205,7 +205,7 @@ public class HttpProxyHandlerTest {
                     @Override
                     protected void initChannel(Channel ch) {
                         ch.pipeline().addFirst(new HttpProxyHandler(addr));
-                        ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                        ch.pipeline().addLast(new ChannelInboundHandler() {
                             @Override
                             public void exceptionCaught(ChannelHandlerContext ctx,
                                 Throwable cause) {

handler-proxy/src/test/java/io/netty/handler/proxy/ProxyServer.java

@@ -25,7 +25,7 @@ import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.EventLoop;
@@ -229,7 +229,7 @@ abstract class ProxyServer {
             ctx.close();
         }
 
-        private final class BackendHandler extends ChannelInboundHandlerAdapter {
+        private final class BackendHandler implements ChannelInboundHandler {
 
             private final ChannelHandlerContext frontend;
 

handler/src/main/java/io/netty/handler/ipfilter/AbstractRemoteAddressFilter.java

@@ -19,7 +19,7 @@ import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 
 import java.net.SocketAddress;
 
@@ -35,7 +35,7 @@ import java.net.SocketAddress;
  * flexibility to respond to rejected (denied) connections. If you do not want to send a response, just have it return
  * null.  Take a look at {@link RuleBasedIpFilter} for details.
  */
-public abstract class AbstractRemoteAddressFilter<T extends SocketAddress> extends ChannelInboundHandlerAdapter {
+public abstract class AbstractRemoteAddressFilter<T extends SocketAddress> implements ChannelInboundHandler {
 
     @Override
     public void channelRegistered(ChannelHandlerContext ctx) throws Exception {

handler/src/main/java/io/netty/handler/ssl/ApplicationProtocolNegotiationHandler.java

@@ -19,7 +19,7 @@ import static java.util.Objects.requireNonNull;
 
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelPipeline;
 import io.netty.util.internal.logging.InternalLogger;
@@ -60,7 +60,7 @@ import io.netty.util.internal.logging.InternalLoggerFactory;
  * }
  * </pre>
  */
-public abstract class ApplicationProtocolNegotiationHandler extends ChannelInboundHandlerAdapter {
+public abstract class ApplicationProtocolNegotiationHandler implements ChannelInboundHandler {
 
     private static final InternalLogger logger =
             InternalLoggerFactory.getInstance(ApplicationProtocolNegotiationHandler.class);

handler/src/main/java/io/netty/handler/ssl/ocsp/OcspClientHandler.java

@@ -18,7 +18,7 @@ package io.netty.handler.ssl.ocsp;
 import static java.util.Objects.requireNonNull;
 
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.handler.ssl.ReferenceCountedOpenSslContext;
 import io.netty.handler.ssl.ReferenceCountedOpenSslEngine;
 import io.netty.handler.ssl.SslHandshakeCompletionEvent;
@@ -34,7 +34,7 @@ import javax.net.ssl.SSLHandshakeException;
  * @see ReferenceCountedOpenSslEngine#getOcspResponse()
  */
 @UnstableApi
-public abstract class OcspClientHandler extends ChannelInboundHandlerAdapter {
+public abstract class OcspClientHandler implements ChannelInboundHandler {
 
     private static final SSLHandshakeException OCSP_VERIFICATION_EXCEPTION = ThrowableUtil.unknownStackTrace(
             new SSLHandshakeException("Bad OCSP response"), OcspClientHandler.class, "verify(...)");

handler/src/main/java/io/netty/handler/timeout/WriteTimeoutHandler.java

@@ -24,7 +24,7 @@ import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInitializer;
-import io.netty.channel.ChannelOutboundHandlerAdapter;
+import io.netty.channel.ChannelOutboundHandler;
 import io.netty.channel.ChannelPromise;
 
 import java.util.concurrent.ScheduledFuture;
@@ -64,7 +64,7 @@ import java.util.concurrent.TimeUnit;
  * @see ReadTimeoutHandler
  * @see IdleStateHandler
  */
-public class WriteTimeoutHandler extends ChannelOutboundHandlerAdapter {
+public class WriteTimeoutHandler implements ChannelOutboundHandler {
     private static final long MIN_TIMEOUT_NANOS = TimeUnit.MILLISECONDS.toNanos(1);
 
     private final long timeoutNanos;

handler/src/test/java/io/netty/handler/flow/FlowControlHandlerTest.java

@@ -21,10 +21,9 @@ import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelConfig;
-import io.netty.channel.ChannelDuplexHandler;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.ChannelPipeline;
@@ -95,7 +94,7 @@ public class FlowControlHandlerTest {
         bootstrap.group(GROUP)
             .channel(NioSocketChannel.class)
             .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 1000)
-            .handler(new ChannelInboundHandlerAdapter() {
+            .handler(new ChannelInboundHandler() {
                 @Override
                 public void channelRead(ChannelHandlerContext ctx, Object msg) {
                     fail("In this test the client is never receiving a message from the server.");
@@ -120,7 +119,7 @@ public class FlowControlHandlerTest {
     public void testAutoReadingOn() throws Exception {
         final CountDownLatch latch = new CountDownLatch(3);
 
-        ChannelInboundHandlerAdapter handler = new ChannelInboundHandlerAdapter() {
+        ChannelInboundHandler handler = new ChannelInboundHandler() {
             @Override
             public void channelRead(ChannelHandlerContext ctx, Object msg) {
                 ReferenceCountUtil.release(msg);
@@ -162,7 +161,7 @@ public class FlowControlHandlerTest {
         final Exchanger<Channel> peerRef = new Exchanger<>();
         final CountDownLatch latch = new CountDownLatch(3);
 
-        ChannelInboundHandlerAdapter handler = new ChannelInboundHandlerAdapter() {
+        ChannelInboundHandler handler = new ChannelInboundHandler() {
             @Override
             public void channelActive(ChannelHandlerContext ctx) throws Exception {
                 peerRef.exchange(ctx.channel(), 1L, SECONDS);
@@ -208,7 +207,7 @@ public class FlowControlHandlerTest {
     public void testFlowAutoReadOn() throws Exception {
         final CountDownLatch latch = new CountDownLatch(3);
 
-        ChannelInboundHandlerAdapter handler = new ChannelDuplexHandler() {
+        ChannelInboundHandler handler = new ChannelInboundHandler() {
             @Override
             public void channelRead(ChannelHandlerContext ctx, Object msg) {
                 latch.countDown();
@@ -245,7 +244,7 @@ public class FlowControlHandlerTest {
         final CountDownLatch setAutoReadLatch1 = new CountDownLatch(1);
         final CountDownLatch setAutoReadLatch2 = new CountDownLatch(1);
 
-        ChannelInboundHandlerAdapter handler = new ChannelInboundHandlerAdapter() {
+        ChannelInboundHandler handler = new ChannelInboundHandler() {
             private int msgRcvCount;
             private int expectedMsgCount;
             @Override
@@ -325,7 +324,7 @@ public class FlowControlHandlerTest {
         final CountDownLatch msgRcvLatch2 = new CountDownLatch(2);
         final CountDownLatch msgRcvLatch3 = new CountDownLatch(3);
 
-        ChannelInboundHandlerAdapter handler = new ChannelDuplexHandler() {
+        ChannelInboundHandler handler = new ChannelInboundHandler() {
             @Override
             public void channelActive(ChannelHandlerContext ctx) throws Exception {
                 ctx.fireChannelActive();

handler/src/test/java/io/netty/handler/flush/FlushConsolidationHandlerTest.java

@@ -16,8 +16,8 @@
 package io.netty.handler.flush;
 
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
-import io.netty.channel.ChannelOutboundHandlerAdapter;
+import io.netty.channel.ChannelOutboundHandler;
 import io.netty.channel.embedded.EmbeddedChannel;
 import org.junit.Test;
 
@@ -154,7 +154,7 @@ public class FlushConsolidationHandlerTest {
 
     private static EmbeddedChannel newChannel(final AtomicInteger flushCount, boolean consolidateWhenNoReadInProgress) {
         return new EmbeddedChannel(
-                new ChannelOutboundHandlerAdapter() {
+                new ChannelOutboundHandler() {
                     @Override
                     public void flush(ChannelHandlerContext ctx) throws Exception {
                         flushCount.incrementAndGet();
@@ -162,7 +162,7 @@ public class FlushConsolidationHandlerTest {
                     }
                 },
                 new FlushConsolidationHandler(EXPLICIT_FLUSH_AFTER_FLUSHES, consolidateWhenNoReadInProgress),
-                new ChannelInboundHandlerAdapter() {
+                new ChannelInboundHandler() {
                     @Override
                     public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
                         ctx.writeAndFlush(msg);

handler/src/test/java/io/netty/handler/ssl/ParameterizedSslHandlerTest.java

@@ -20,10 +20,9 @@ import io.netty.bootstrap.ServerBootstrap;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.CompositeByteBuf;
 import io.netty.channel.Channel;
-import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.EventLoopGroup;
 import io.netty.channel.MultithreadEventLoopGroup;
@@ -35,7 +34,6 @@ import io.netty.handler.ssl.util.SelfSignedCertificate;
 import io.netty.handler.ssl.util.SimpleTrustManagerFactory;
 import io.netty.util.ReferenceCountUtil;
 import io.netty.util.internal.ResourcesUtil;
-import io.netty.util.concurrent.Future;
 import io.netty.util.concurrent.FutureListener;
 import io.netty.util.concurrent.Promise;
 import io.netty.util.concurrent.PromiseNotifier;
@@ -154,7 +152,7 @@ public class ParameterizedSslHandlerTest {
                                 handler.setWrapDataSize(-1);
                             }
                             ch.pipeline().addLast(handler);
-                            ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                            ch.pipeline().addLast(new ChannelInboundHandler() {
                                 private boolean sentData;
                                 private Throwable writeCause;
 
@@ -208,7 +206,7 @@ public class ParameterizedSslHandlerTest {
                             } else {
                                 ch.pipeline().addLast(new SslHandler(sslClientCtx.newEngine(ch.alloc())));
                             }
-                            ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                            ch.pipeline().addLast(new ChannelInboundHandler() {
                                 private int bytesSeen;
                                 @Override
                                 public void channelRead(ChannelHandlerContext ctx, Object msg) {
@@ -316,7 +314,7 @@ public class ParameterizedSslHandlerTest {
                         @Override
                         protected void initChannel(Channel ch) throws Exception {
                             ch.pipeline().addLast(sslServerCtx.newHandler(ch.alloc()));
-                            ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                            ch.pipeline().addLast(new ChannelInboundHandler() {
                                 @Override
                                 public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
                                     // Just trigger a close
@@ -333,7 +331,7 @@ public class ParameterizedSslHandlerTest {
                         @Override
                         protected void initChannel(Channel ch) throws Exception {
                             ch.pipeline().addLast(sslClientCtx.newHandler(ch.alloc()));
-                            ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                            ch.pipeline().addLast(new ChannelInboundHandler() {
                                 @Override
                                 public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
                                     if (cause.getCause() instanceof SSLException) {
@@ -430,7 +428,7 @@ public class ParameterizedSslHandlerTest {
                         protected void initChannel(Channel ch) throws Exception {
                             final AtomicBoolean closeSent = new AtomicBoolean();
                             if (timeout) {
-                                ch.pipeline().addFirst(new ChannelInboundHandlerAdapter() {
+                                ch.pipeline().addFirst(new ChannelInboundHandler() {
                                     @Override
                                     public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
                                         if (closeSent.get()) {
@@ -438,7 +436,7 @@ public class ParameterizedSslHandlerTest {
                                             // close_notify.
                                             ReferenceCountUtil.release(msg);
                                         } else {
-                                            super.channelRead(ctx, msg);
+                                            ctx.fireChannelRead(msg);
                                         }
                                     }
                                 });

handler/src/test/java/io/netty/handler/ssl/RenegotiateTest.java

@@ -19,7 +19,7 @@ import io.netty.bootstrap.Bootstrap;
 import io.netty.bootstrap.ServerBootstrap;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.EventLoopGroup;
 import io.netty.channel.MultithreadEventLoopGroup;
@@ -30,7 +30,6 @@ import io.netty.channel.local.LocalServerChannel;
 import io.netty.handler.ssl.util.InsecureTrustManagerFactory;
 import io.netty.handler.ssl.util.SelfSignedCertificate;
 import io.netty.util.ReferenceCountUtil;
-import io.netty.util.concurrent.Future;
 import io.netty.util.concurrent.FutureListener;
 import org.junit.Test;
 
@@ -54,7 +53,7 @@ public abstract class RenegotiateTest {
                         @Override
                         protected void initChannel(Channel ch) throws Exception {
                             ch.pipeline().addLast(context.newHandler(ch.alloc()));
-                            ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                            ch.pipeline().addLast(new ChannelInboundHandler() {
                                 private boolean renegotiate;
 
                                 @Override
@@ -101,7 +100,7 @@ public abstract class RenegotiateTest {
                         @Override
                         protected void initChannel(Channel ch) throws Exception {
                             ch.pipeline().addLast(clientContext.newHandler(ch.alloc()));
-                            ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                            ch.pipeline().addLast(new ChannelInboundHandler() {
                                 @Override
                                 public void userEventTriggered(
                                         ChannelHandlerContext ctx, Object evt) throws Exception {

handler/src/test/java/io/netty/handler/ssl/SSLEngineTest.java

@@ -25,7 +25,7 @@ import io.netty.buffer.UnpooledByteBufAllocator;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.MultithreadEventLoopGroup;
@@ -740,7 +740,7 @@ public abstract class SSLEngineTest {
                 }
                 p.addLast(handler);
                 p.addLast(new MessageDelegatorChannelHandler(serverReceiver, serverLatch));
-                p.addLast(new ChannelInboundHandlerAdapter() {
+                p.addLast(new ChannelInboundHandler() {
                     @Override
                     public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
                         if (evt == SslHandshakeCompletionEvent.SUCCESS) {
@@ -782,7 +782,7 @@ public abstract class SSLEngineTest {
                         clientSslCtx.newHandler(ch.alloc(), delegatingExecutor);
                 p.addLast(handler);
                 p.addLast(new MessageDelegatorChannelHandler(clientReceiver, clientLatch));
-                p.addLast(new ChannelInboundHandlerAdapter() {
+                p.addLast(new ChannelInboundHandler() {
                     @Override
                     public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
                         if (evt == SslHandshakeCompletionEvent.SUCCESS) {
@@ -889,7 +889,7 @@ public abstract class SSLEngineTest {
                         serverSslCtx.newHandler(ch.alloc(), delegatingExecutor);
                 p.addLast(handler);
                 p.addLast(new MessageDelegatorChannelHandler(serverReceiver, serverLatch));
-                p.addLast(new ChannelInboundHandlerAdapter() {
+                p.addLast(new ChannelInboundHandler() {
                     @Override
                     public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
                         if (evt == SslHandshakeCompletionEvent.SUCCESS) {
@@ -941,7 +941,7 @@ public abstract class SSLEngineTest {
                 sslHandler.engine().setSSLParameters(parameters);
                 p.addLast(sslHandler);
                 p.addLast(new MessageDelegatorChannelHandler(clientReceiver, clientLatch));
-                p.addLast(new ChannelInboundHandlerAdapter() {
+                p.addLast(new ChannelInboundHandler() {
                     @Override
                     public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
                         if (evt == SslHandshakeCompletionEvent.SUCCESS) {
@@ -1061,7 +1061,7 @@ public abstract class SSLEngineTest {
 
                 p.addLast(new SslHandler(engine));
                 p.addLast(new MessageDelegatorChannelHandler(serverReceiver, serverLatch));
-                p.addLast(new ChannelInboundHandlerAdapter() {
+                p.addLast(new ChannelInboundHandler() {
                     @Override
                     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
                         if (cause.getCause() instanceof SSLHandshakeException) {
@@ -1104,7 +1104,7 @@ public abstract class SSLEngineTest {
                 ChannelPipeline p = ch.pipeline();
                 p.addLast(handler);
                 p.addLast(new MessageDelegatorChannelHandler(clientReceiver, clientLatch));
-                p.addLast(new ChannelInboundHandlerAdapter() {
+                p.addLast(new ChannelInboundHandler() {
                     @Override
                     public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
                         if (evt == SslHandshakeCompletionEvent.SUCCESS) {
@@ -1300,7 +1300,7 @@ public abstract class SSLEngineTest {
                                 serverSslCtx.newHandler(ch.alloc(), delegatingExecutor);
 
                         p.addLast(handler);
-                        p.addLast(new ChannelInboundHandlerAdapter() {
+                        p.addLast(new ChannelInboundHandler() {
                             @Override
                             public void userEventTriggered(ChannelHandlerContext ctx, Object evt) {
                                 if (evt instanceof SslHandshakeCompletionEvent &&
@@ -1361,7 +1361,7 @@ public abstract class SSLEngineTest {
                         // the unit test can terminate relativley quicly.
                         sslHandler.setHandshakeTimeout(1, TimeUnit.SECONDS);
                         p.addLast(sslHandler);
-                        p.addLast(new ChannelInboundHandlerAdapter() {
+                        p.addLast(new ChannelInboundHandler() {
                             private int handshakeCount;
                             @Override
                             public void userEventTriggered(ChannelHandlerContext ctx, Object evt) {
@@ -1650,7 +1650,7 @@ public abstract class SSLEngineTest {
 
                 p.addLast(sslHandler);
                 p.addLast(new MessageDelegatorChannelHandler(serverReceiver, serverLatch));
-                p.addLast(new ChannelInboundHandlerAdapter() {
+                p.addLast(new ChannelInboundHandler() {
                     @Override
                     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
                         if (cause.getCause() instanceof SSLHandshakeException) {
@@ -1680,7 +1680,7 @@ public abstract class SSLEngineTest {
 
                 p.addLast(sslHandler);
                 p.addLast(new MessageDelegatorChannelHandler(clientReceiver, clientLatch));
-                p.addLast(new ChannelInboundHandlerAdapter() {
+                p.addLast(new ChannelInboundHandler() {
                     @Override
                     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
                         if (cause.getCause() instanceof SSLHandshakeException) {
@@ -1734,7 +1734,7 @@ public abstract class SSLEngineTest {
                         serverSslCtx.newHandler(ch.alloc(), delegatingExecutor);
 
                 ch.pipeline().addFirst(sslHandler);
-                ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                ch.pipeline().addLast(new ChannelInboundHandler() {
                     @Override
                     public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
                         if (evt instanceof SslHandshakeCompletionEvent) {

handler/src/test/java/io/netty/handler/ssl/SniClientJava8TestUtil.java

@@ -20,7 +20,7 @@ import io.netty.bootstrap.ServerBootstrap;
 import io.netty.buffer.ByteBufAllocator;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.MultithreadEventLoopGroup;
 import io.netty.channel.EventLoopGroup;
@@ -108,7 +108,7 @@ final class SniClientJava8TestUtil {
                     handler.engine().setSSLParameters(parameters);
 
                     ch.pipeline().addFirst(handler);
-                    ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                    ch.pipeline().addLast(new ChannelInboundHandler() {
                         @Override
                         public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
                             if (evt instanceof SslHandshakeCompletionEvent) {

handler/src/test/java/io/netty/handler/ssl/SniHandlerTest.java

@@ -24,7 +24,7 @@ import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.MultithreadEventLoopGroup;
@@ -149,7 +149,7 @@ public class SniHandlerTest {
             final AtomicReference<SslHandshakeCompletionEvent> evtRef =
                     new AtomicReference<>();
             SniHandler handler = new SniHandler(new DomainNameMappingBuilder<>(nettyContext).build());
-            EmbeddedChannel ch = new EmbeddedChannel(handler, new ChannelInboundHandlerAdapter() {
+            EmbeddedChannel ch = new EmbeddedChannel(handler, new ChannelInboundHandler() {
                 @Override
                 public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
                     if (evt instanceof SslHandshakeCompletionEvent) {
@@ -196,7 +196,7 @@ public class SniHandlerTest {
 
             final AtomicReference<SniCompletionEvent> evtRef = new AtomicReference<>();
             SniHandler handler = new SniHandler(mapping);
-            EmbeddedChannel ch = new EmbeddedChannel(handler, new ChannelInboundHandlerAdapter() {
+            EmbeddedChannel ch = new EmbeddedChannel(handler, new ChannelInboundHandler() {
                 @Override
                 public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
                     if (evt instanceof SniCompletionEvent) {

handler/src/test/java/io/netty/handler/ssl/SslErrorTest.java

@@ -19,7 +19,7 @@ import io.netty.bootstrap.Bootstrap;
 import io.netty.bootstrap.ServerBootstrap;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.EventLoopGroup;
 import io.netty.channel.MultithreadEventLoopGroup;
@@ -174,7 +174,7 @@ public class SslErrorTest {
                         @Override
                         protected void initChannel(Channel ch) throws Exception {
                             ch.pipeline().addLast(sslServerCtx.newHandler(ch.alloc()));
-                            ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                            ch.pipeline().addLast(new ChannelInboundHandler() {
 
                                 @Override
                                 public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
@@ -192,7 +192,7 @@ public class SslErrorTest {
                         @Override
                         protected void initChannel(Channel ch) throws Exception {
                             ch.pipeline().addLast(sslClientCtx.newHandler(ch.alloc()));
-                            ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                            ch.pipeline().addLast(new ChannelInboundHandler() {
                                 @Override
                                 public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
                                     // Unwrap as its wrapped by a DecoderException

handler/src/test/java/io/netty/handler/ssl/SslHandlerTest.java

@@ -27,9 +27,9 @@ import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
-import io.netty.channel.ChannelOutboundHandlerAdapter;
+import io.netty.channel.ChannelOutboundHandler;
 import io.netty.channel.ChannelPromise;
 import io.netty.channel.DefaultChannelId;
 import io.netty.channel.MultithreadEventLoopGroup;
@@ -95,7 +95,7 @@ public class SslHandlerTest {
 
         SSLEngine engine = SSLContext.getDefault().createSSLEngine();
         EmbeddedChannel ch = new EmbeddedChannel(
-                DefaultChannelId.newInstance(), false, false, new ChannelInboundHandlerAdapter() {
+                DefaultChannelId.newInstance(), false, false, new ChannelInboundHandler() {
             @Override
             public void channelActive(ChannelHandlerContext ctx) throws Exception {
                 // Not forward the event to the SslHandler but just close the Channel.
@@ -110,7 +110,7 @@ public class SslHandlerTest {
                 super.handlerAdded(ctx);
                 inActive.set(false);
             }
-        }, new ChannelInboundHandlerAdapter() {
+        }, new ChannelInboundHandler() {
             @Override
             public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
                 if (evt instanceof SslHandshakeCompletionEvent) {
@@ -274,13 +274,13 @@ public class SslHandlerTest {
         }
     }
 
-    private static final class TlsReadTest extends ChannelOutboundHandlerAdapter {
+    private static final class TlsReadTest implements ChannelOutboundHandler {
         private volatile boolean readIssued;
 
         @Override
         public void read(ChannelHandlerContext ctx) throws Exception {
             readIssued = true;
-            super.read(ctx);
+            ctx.read();
         }
 
         public void test(final boolean dropChannelActive) throws Exception {
@@ -290,7 +290,7 @@ public class SslHandlerTest {
             EmbeddedChannel ch = new EmbeddedChannel(false, false,
                     this,
                     new SslHandler(engine),
-                    new ChannelInboundHandlerAdapter() {
+                    new ChannelInboundHandler() {
                         @Override
                         public void channelActive(ChannelHandlerContext ctx) throws Exception {
                             if (!dropChannelActive) {
@@ -375,7 +375,7 @@ public class SslHandlerTest {
                     ch.eventLoop().execute(ch::close);
                 });
 
-                ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                ch.pipeline().addLast(new ChannelInboundHandler() {
                     @Override
                     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
                         if (cause instanceof CodecException) {
@@ -418,7 +418,7 @@ public class SslHandlerTest {
     public void testEventsFired() throws Exception {
         SSLEngine engine = newServerModeSSLEngine();
         final BlockingQueue<SslCompletionEvent> events = new LinkedBlockingQueue<>();
-        EmbeddedChannel channel = new EmbeddedChannel(new SslHandler(engine), new ChannelInboundHandlerAdapter() {
+        EmbeddedChannel channel = new EmbeddedChannel(new SslHandler(engine), new ChannelInboundHandler() {
             @Override
             public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
                 if (evt instanceof SslCompletionEvent) {
@@ -457,7 +457,7 @@ public class SslHandlerTest {
                   @Override
                   protected void initChannel(Channel ch) {
                       ch.pipeline().addLast(sslServerCtx.newHandler(ch.alloc()));
-                      ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                      ch.pipeline().addLast(new ChannelInboundHandler() {
                           @Override
                           public void channelActive(ChannelHandlerContext ctx) {
                               ByteBuf buf = ctx.alloc().buffer(10);
@@ -486,7 +486,7 @@ public class SslHandlerTest {
                 .handler(new ChannelInitializer<Channel>() {
                     @Override
                     protected void initChannel(Channel ch) {
-                        ch.pipeline().addFirst(new ChannelInboundHandlerAdapter() {
+                        ch.pipeline().addFirst(new ChannelInboundHandler() {
                             @Override
                             public void channelActive(ChannelHandlerContext ctx) {
                                 ByteBuf buf = ctx.alloc().buffer(1000);
@@ -691,7 +691,7 @@ public class SslHandlerTest {
             sc = new ServerBootstrap()
                     .group(group)
                     .channel(NioServerSocketChannel.class)
-                    .childHandler(new ChannelInboundHandlerAdapter())
+                    .childHandler(new ChannelInboundHandler() { })
                     .bind(new InetSocketAddress(0)).syncUninterruptibly().channel();
 
             cc = new Bootstrap()
@@ -701,7 +701,7 @@ public class SslHandlerTest {
                         @Override
                         protected void initChannel(Channel ch) throws Exception {
                             ch.pipeline().addLast(sslHandler);
-                            ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                            ch.pipeline().addLast(new ChannelInboundHandler() {
                                 @Override
                                 public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
                                         throws Exception {
@@ -770,7 +770,7 @@ public class SslHandlerTest {
             sc = new ServerBootstrap()
                     .group(group)
                     .channel(NioServerSocketChannel.class)
-                    .childHandler(new ChannelInboundHandlerAdapter())
+                    .childHandler(new ChannelInboundHandler() { })
                     .bind(new InetSocketAddress(0)).syncUninterruptibly().channel();
 
             ChannelFuture future = new Bootstrap()
@@ -781,7 +781,7 @@ public class SslHandlerTest {
                         protected void initChannel(Channel ch) throws Exception {
                             ch.pipeline().addLast(sslHandler);
                             if (startTls) {
-                                ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                                ch.pipeline().addLast(new ChannelInboundHandler() {
                                     @Override
                                     public void channelActive(ChannelHandlerContext ctx) throws Exception {
                                         ctx.writeAndFlush(wrappedBuffer(new byte[] { 1, 2, 3, 4 }));

handler/src/test/java/io/netty/handler/ssl/ocsp/OcspTest.java

@@ -23,7 +23,7 @@ import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.MultithreadEventLoopGroup;
@@ -164,7 +164,7 @@ public class OcspTest {
      */
     private static void testClientAcceptingOcspStaple(SslProvider sslProvider) throws Exception {
         final CountDownLatch latch = new CountDownLatch(1);
-        ChannelInboundHandlerAdapter serverHandler = new ChannelInboundHandlerAdapter() {
+        ChannelInboundHandler serverHandler = new ChannelInboundHandler() {
             @Override
             public void channelActive(ChannelHandlerContext ctx) throws Exception {
                 ctx.writeAndFlush(Unpooled.wrappedBuffer("Hello, World!".getBytes()));
@@ -172,7 +172,7 @@ public class OcspTest {
             }
         };
 
-        ChannelInboundHandlerAdapter clientHandler = new ChannelInboundHandlerAdapter() {
+        ChannelInboundHandler clientHandler = new ChannelInboundHandler() {
             @Override
             public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
                 try {
@@ -212,7 +212,7 @@ public class OcspTest {
         final AtomicReference<Throwable> causeRef = new AtomicReference<>();
         final CountDownLatch latch = new CountDownLatch(1);
 
-        ChannelInboundHandlerAdapter clientHandler = new ChannelInboundHandlerAdapter() {
+        ChannelInboundHandler clientHandler = new ChannelInboundHandler() {
             @Override
             public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
                 try {
@@ -253,7 +253,7 @@ public class OcspTest {
      */
     private static void testServerHasNoStaple(SslProvider sslProvider) throws Exception {
         final CountDownLatch latch = new CountDownLatch(1);
-        ChannelInboundHandlerAdapter serverHandler = new ChannelInboundHandlerAdapter() {
+        ChannelInboundHandler serverHandler = new ChannelInboundHandler() {
             @Override
             public void channelActive(ChannelHandlerContext ctx) throws Exception {
                 ctx.writeAndFlush(Unpooled.wrappedBuffer("Hello, World!".getBytes()));
@@ -261,7 +261,7 @@ public class OcspTest {
             }
         };
 
-        ChannelInboundHandlerAdapter clientHandler = new ChannelInboundHandlerAdapter() {
+        ChannelInboundHandler clientHandler = new ChannelInboundHandler() {
             @Override
             public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
                 try {
@@ -302,7 +302,7 @@ public class OcspTest {
         final AtomicReference<Throwable> causeRef = new AtomicReference<>();
         final CountDownLatch latch = new CountDownLatch(1);
 
-        ChannelInboundHandlerAdapter clientHandler = new ChannelInboundHandlerAdapter() {
+        ChannelInboundHandler clientHandler = new ChannelInboundHandler() {
             @Override
             public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
                 try {

handler/src/test/java/io/netty/handler/stream/ChunkedWriteHandlerTest.java

@@ -21,7 +21,7 @@ import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelOutboundHandlerAdapter;
+import io.netty.channel.ChannelOutboundHandler;
 import io.netty.channel.ChannelPromise;
 import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.util.CharsetUtil;
@@ -273,7 +273,7 @@ public class ChunkedWriteHandlerTest {
     // See https://github.com/netty/netty/issues/8700.
     @Test
     public void testFailureWhenLastChunkFailed() throws IOException {
-        ChannelOutboundHandlerAdapter failLast = new ChannelOutboundHandlerAdapter() {
+        ChannelOutboundHandler failLast = new ChannelOutboundHandler() {
             private int passedWrites;
 
             @Override
@@ -409,7 +409,7 @@ public class ChunkedWriteHandlerTest {
             }
         };
 
-        ChannelOutboundHandlerAdapter noOpWrites = new ChannelOutboundHandlerAdapter() {
+        ChannelOutboundHandler noOpWrites = new ChannelOutboundHandler() {
             @Override
             public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) {
                 ReferenceCountUtil.release(msg);
@@ -595,7 +595,7 @@ public class ChunkedWriteHandlerTest {
     }
 
     private static void checkFirstFailed(Object input) {
-        ChannelOutboundHandlerAdapter noOpWrites = new ChannelOutboundHandlerAdapter() {
+        ChannelOutboundHandler noOpWrites = new ChannelOutboundHandler() {
             @Override
             public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) {
                 ReferenceCountUtil.release(msg);
@@ -612,7 +612,7 @@ public class ChunkedWriteHandlerTest {
     }
 
     private static void checkSkipFailed(Object input1, Object input2) {
-        ChannelOutboundHandlerAdapter failFirst = new ChannelOutboundHandlerAdapter() {
+        ChannelOutboundHandler failFirst = new ChannelOutboundHandler() {
             private boolean alreadyFailed;
 
             @Override

handler/src/test/java/io/netty/handler/timeout/IdleStateHandlerTest.java

@@ -25,7 +25,7 @@ import static org.junit.Assert.assertTrue;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelOutboundBuffer;
 import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.util.ReferenceCountUtil;
@@ -72,7 +72,7 @@ public class IdleStateHandlerTest {
         assertTrue("The number of expected events must be >= 1", expected.length >= 1);
 
         final List<Object> events = new ArrayList<>();
-        ChannelInboundHandlerAdapter handler = new ChannelInboundHandlerAdapter() {
+        ChannelInboundHandler handler = new ChannelInboundHandler() {
             @Override
             public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
                 events.add(evt);
@@ -143,7 +143,7 @@ public class IdleStateHandlerTest {
                                    Action action, Object expected) throws Exception {
 
         final List<Object> events = new ArrayList<>();
-        ChannelInboundHandlerAdapter handler = new ChannelInboundHandlerAdapter() {
+        ChannelInboundHandler handler = new ChannelInboundHandler() {
             @Override
             public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
                 events.add(evt);
@@ -203,7 +203,7 @@ public class IdleStateHandlerTest {
                 true, 0L, writerIdleTime, allIdleTime, TimeUnit.SECONDS);
 
         final List<Object> events = new ArrayList<>();
-        ChannelInboundHandlerAdapter handler = new ChannelInboundHandlerAdapter() {
+        ChannelInboundHandler handler = new ChannelInboundHandler() {
             @Override
             public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
                 events.add(evt);

microbench/src/main/java/io/netty/handler/codec/http2/Http2FrameWriterDataBenchmark.java

@@ -20,7 +20,7 @@ import io.netty.buffer.Unpooled;
 import io.netty.buffer.UnpooledByteBufAllocator;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelPromise;
 import io.netty.microbench.channel.EmbeddedChannelWriteReleaseHandlerContext;
 import io.netty.microbench.util.AbstractMicrobenchmark;
@@ -79,7 +79,7 @@ public class Http2FrameWriterDataBenchmark extends AbstractMicrobenchmark {
         payload.writeZero(payloadSize);
         ctx = new EmbeddedChannelWriteReleaseHandlerContext(
                 pooled ? PooledByteBufAllocator.DEFAULT : UnpooledByteBufAllocator.DEFAULT,
-                new ChannelInboundHandlerAdapter()) {
+                new ChannelInboundHandler() { }) {
             @Override
             protected void handleException(Throwable t) {
                 handleUnexpectedException(t);

microbench/src/main/java/io/netty/microbench/channel/DefaultChannelPipelineBenchmark.java

@@ -15,9 +15,9 @@
  */
 package io.netty.microbench.channel;
 
+import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInboundHandler;
-import io.netty.channel.ChannelInboundHandlerAdapter;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.microbench.util.AbstractMicrobenchmark;
@@ -37,23 +37,15 @@ import org.openjdk.jmh.infra.Blackhole;
 @State(Scope.Benchmark)
 public class DefaultChannelPipelineBenchmark extends AbstractMicrobenchmark {
 
-    private static final ChannelInboundHandler NOOP_HANDLER = new ChannelInboundHandlerAdapter() {
+    @ChannelHandler.Sharable
-        @Override
+    private static final ChannelInboundHandler NOOP_HANDLER = new ChannelInboundHandler() { };
-        public boolean isSharable() {
-            return true;
-        }
-    };
 
-    private static final ChannelInboundHandler CONSUMING_HANDLER = new ChannelInboundHandlerAdapter() {
+    @ChannelHandler.Sharable
+    private static final ChannelInboundHandler CONSUMING_HANDLER = new ChannelInboundHandler() {
         @Override
         public void channelReadComplete(ChannelHandlerContext ctx) {
             // NOOP
         }
-
-        @Override
-        public boolean isSharable() {
-            return true;
-        }
     };
 
     @Param({ "4" })

resolver-dns/src/main/java/io/netty/resolver/dns/DnsNameResolver.java

@@ -24,7 +24,7 @@ import io.netty.channel.ChannelFactory;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.ChannelPromise;
@@ -1111,7 +1111,7 @@ public class DnsNameResolver extends InetNameResolver {
         return dnsServerAddressStreamProvider.nameServerAddressStream(hostname);
     }
 
-    private final class DnsResponseHandler extends ChannelInboundHandlerAdapter {
+    private final class DnsResponseHandler implements ChannelInboundHandler {
 
         private final Promise<Channel> channelActivePromise;
 
@@ -1143,7 +1143,7 @@ public class DnsNameResolver extends InetNameResolver {
 
         @Override
         public void channelActive(ChannelHandlerContext ctx) throws Exception {
-            super.channelActive(ctx);
+            ctx.fireChannelActive();
             channelActivePromise.setSuccess(ctx.channel());
         }
 

testsuite-autobahn/src/main/java/io/netty/testsuite/autobahn/AutobahnServerHandler.java

@@ -20,7 +20,7 @@ import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.handler.codec.http.DefaultFullHttpResponse;
 import io.netty.handler.codec.http.FullHttpResponse;
 import io.netty.handler.codec.http.HttpHeaderNames;
@@ -48,7 +48,7 @@ import static io.netty.handler.codec.http.HttpVersion.*;
 /**
  * Handles handshakes and messages
  */
-public class AutobahnServerHandler extends ChannelInboundHandlerAdapter {
+public class AutobahnServerHandler implements ChannelInboundHandler {
     private static final Logger logger = Logger.getLogger(AutobahnServerHandler.class.getName());
 
     private WebSocketServerHandshaker handshaker;

testsuite-http2/src/main/java/io/netty/testsuite/http2/Http2ServerInitializer.java

@@ -19,7 +19,7 @@ package io.netty.testsuite.http2;
 import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
 
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.SimpleChannelInboundHandler;
@@ -28,7 +28,6 @@ import io.netty.handler.codec.http.HttpMessage;
 import io.netty.handler.codec.http.HttpObjectAggregator;
 import io.netty.handler.codec.http.HttpServerCodec;
 import io.netty.handler.codec.http.HttpServerUpgradeHandler;
-import io.netty.handler.codec.http.HttpServerUpgradeHandler.UpgradeCodec;
 import io.netty.handler.codec.http.HttpServerUpgradeHandler.UpgradeCodecFactory;
 import io.netty.handler.codec.http2.CleartextHttp2ServerUpgradeHandler;
 import io.netty.handler.codec.http2.Http2CodecUtil;
@@ -97,7 +96,7 @@ public class Http2ServerInitializer extends ChannelInitializer<SocketChannel> {
     /**
      * Class that logs any User Events triggered on this channel.
      */
-    private static class UserEventLogger extends ChannelInboundHandlerAdapter {
+    private static class UserEventLogger implements ChannelInboundHandler {
         @Override
         public void userEventTriggered(ChannelHandlerContext ctx, Object evt) {
             System.out.println("User Event Triggered: " + evt);

testsuite/src/main/java/io/netty/testsuite/transport/socket/CompositeBufferGatheringWriteTest.java

@@ -24,7 +24,7 @@ import io.netty.channel.Channel;
 import io.netty.channel.ChannelConfig;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelOption;
 import io.netty.util.ReferenceCountUtil;
@@ -54,7 +54,7 @@ public class CompositeBufferGatheringWriteTest extends AbstractSocketTest {
             sb.childHandler(new ChannelInitializer<Channel>() {
                 @Override
                 protected void initChannel(Channel ch) throws Exception {
-                    ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                    ch.pipeline().addLast(new ChannelInboundHandler() {
                         @Override
                         public void channelActive(ChannelHandlerContext ctx) throws Exception {
                             ctx.writeAndFlush(newCompositeBuffer(ctx.alloc()))
@@ -66,7 +66,7 @@ public class CompositeBufferGatheringWriteTest extends AbstractSocketTest {
             cb.handler(new ChannelInitializer<Channel>() {
                 @Override
                 protected void initChannel(Channel ch) throws Exception {
-                    ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                    ch.pipeline().addLast(new ChannelInboundHandler() {
                         private ByteBuf aggregator;
                         @Override
                         public void handlerAdded(ChannelHandlerContext ctx) {
@@ -164,7 +164,7 @@ public class CompositeBufferGatheringWriteTest extends AbstractSocketTest {
               .childHandler(new ChannelInitializer<Channel>() {
                 @Override
                 protected void initChannel(Channel ch) throws Exception {
-                    ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                    ch.pipeline().addLast(new ChannelInboundHandler() {
                         @Override
                         public void channelActive(ChannelHandlerContext ctx) throws Exception {
                             compositeBufferPartialWriteDoesNotCorruptDataInitServerConfig(ctx.channel().config(),
@@ -208,7 +208,7 @@ public class CompositeBufferGatheringWriteTest extends AbstractSocketTest {
             cb.handler(new ChannelInitializer<Channel>() {
                 @Override
                 protected void initChannel(Channel ch) throws Exception {
-                    ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                    ch.pipeline().addLast(new ChannelInboundHandler() {
                         private ByteBuf aggregator;
                         @Override
                         public void handlerAdded(ChannelHandlerContext ctx) {

testsuite/src/main/java/io/netty/testsuite/transport/socket/DatagramConnectNotExistsTest.java

@@ -20,7 +20,7 @@ import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.testsuite.transport.TestsuitePermutation;
 import io.netty.util.CharsetUtil;
 import io.netty.util.NetUtil;
@@ -46,7 +46,7 @@ public class DatagramConnectNotExistsTest extends AbstractClientSocketTest {
 
     public void testConnectNotExists(Bootstrap cb) throws Throwable {
         final Promise<Throwable> promise = ImmediateEventExecutor.INSTANCE.newPromise();
-        cb.handler(new ChannelInboundHandlerAdapter() {
+        cb.handler(new ChannelInboundHandler() {
             @Override
             public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
                 promise.trySuccess(cause);

testsuite/src/main/java/io/netty/testsuite/transport/socket/ServerSocketSuspendTest.java

@@ -19,7 +19,7 @@ import io.netty.bootstrap.ServerBootstrap;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelOption;
 import io.netty.util.internal.SocketUtils;
 import org.junit.Ignore;
@@ -94,7 +94,7 @@ public class ServerSocketSuspendTest extends AbstractServerSocketTest {
     }
 
     @ChannelHandler.Sharable
-    private static final class AcceptedChannelCounter extends ChannelInboundHandlerAdapter {
+    private static final class AcceptedChannelCounter implements ChannelInboundHandler {
 
         final CountDownLatch latch;
 

testsuite/src/main/java/io/netty/testsuite/transport/socket/SocketAutoReadTest.java

@@ -23,7 +23,7 @@ import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelConfig;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.RecvByteBufAllocator;
@@ -116,7 +116,7 @@ public class SocketAutoReadTest extends AbstractSocketTest {
         }
     }
 
-    private static final class AutoReadHandler extends ChannelInboundHandlerAdapter {
+    private static final class AutoReadHandler implements ChannelInboundHandler {
         private final AtomicInteger count = new AtomicInteger();
         private final CountDownLatch latch = new CountDownLatch(1);
         private final CountDownLatch latch2;

testsuite/src/main/java/io/netty/testsuite/transport/socket/SocketChannelNotYetConnectedTest.java

@@ -16,7 +16,7 @@
 package io.netty.testsuite.transport.socket;
 
 import io.netty.bootstrap.Bootstrap;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.socket.SocketChannel;
 import org.junit.Test;
 
@@ -32,7 +32,7 @@ public class SocketChannelNotYetConnectedTest extends AbstractClientSocketTest {
     }
 
     public void testShutdownNotYetConnected(Bootstrap cb) throws Throwable {
-        SocketChannel ch = (SocketChannel) cb.handler(new ChannelInboundHandlerAdapter())
+        SocketChannel ch = (SocketChannel) cb.handler(new ChannelInboundHandler() { })
                 .bind(newSocketAddress()).syncUninterruptibly().channel();
         try {
             try {

testsuite/src/main/java/io/netty/testsuite/transport/socket/SocketCloseForciblyTest.java

@@ -19,7 +19,7 @@ import io.netty.bootstrap.Bootstrap;
 import io.netty.bootstrap.ServerBootstrap;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.socket.SocketChannel;
 import org.junit.Test;
 
@@ -31,7 +31,7 @@ public class SocketCloseForciblyTest extends AbstractSocketTest {
     }
 
     public void testCloseForcibly(ServerBootstrap sb, Bootstrap cb) throws Throwable {
-        sb.handler(new ChannelInboundHandlerAdapter() {
+        sb.handler(new ChannelInboundHandler() {
             @Override
             public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
                 final SocketChannel childChannel = (SocketChannel) msg;
@@ -41,9 +41,9 @@ public class SocketCloseForciblyTest extends AbstractSocketTest {
                     childChannel.unsafe().closeForcibly();
                 });
             }
-        }).childHandler(new ChannelInboundHandlerAdapter());
+        }).childHandler(new ChannelInboundHandler() { });
 
-        cb.handler(new ChannelInboundHandlerAdapter());
+        cb.handler(new ChannelInboundHandler() { });
 
         Channel sc = sb.bind().sync().channel();
 

testsuite/src/main/java/io/netty/testsuite/transport/socket/SocketConditionalWritabilityTest.java

@@ -21,7 +21,7 @@ import io.netty.buffer.ByteBuf;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelDuplexHandler;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.WriteBufferWaterMark;
@@ -90,7 +90,7 @@ public class SocketConditionalWritabilityTest extends AbstractSocketTest {
             cb.handler(new ChannelInitializer<Channel>() {
                 @Override
                 protected void initChannel(Channel ch) {
-                    ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                    ch.pipeline().addLast(new ChannelInboundHandler() {
                         private int totalRead;
                         @Override
                         public void channelActive(ChannelHandlerContext ctx) {

testsuite/src/main/java/io/netty/testsuite/transport/socket/SocketConnectTest.java

@@ -20,7 +20,7 @@ import io.netty.bootstrap.ServerBootstrap;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.util.concurrent.ImmediateEventExecutor;
 import io.netty.util.concurrent.Promise;
 import org.junit.Test;
@@ -43,14 +43,14 @@ public class SocketConnectTest extends AbstractSocketTest {
         Channel clientChannel = null;
         try {
             final Promise<InetSocketAddress> localAddressPromise = ImmediateEventExecutor.INSTANCE.newPromise();
-            serverChannel = sb.childHandler(new ChannelInboundHandlerAdapter() {
+            serverChannel = sb.childHandler(new ChannelInboundHandler() {
                         @Override
                         public void channelActive(ChannelHandlerContext ctx) throws Exception {
                             localAddressPromise.setSuccess((InetSocketAddress) ctx.channel().localAddress());
                         }
                     }).bind().syncUninterruptibly().channel();
 
-            clientChannel = cb.handler(new ChannelInboundHandlerAdapter()).register().syncUninterruptibly().channel();
+            clientChannel = cb.handler(new ChannelInboundHandler() { }).register().syncUninterruptibly().channel();
 
             assertNull(clientChannel.localAddress());
             assertNull(clientChannel.remoteAddress());
@@ -81,10 +81,10 @@ public class SocketConnectTest extends AbstractSocketTest {
         Channel sc = null;
         Channel cc = null;
         try {
-            sb.childHandler(new ChannelInboundHandlerAdapter());
+            sb.childHandler(new ChannelInboundHandler() { });
             sc = sb.bind().syncUninterruptibly().channel();
 
-            cb.handler(new ChannelInboundHandlerAdapter() {
+            cb.handler(new ChannelInboundHandler() {
                 @Override
                 public void channelActive(ChannelHandlerContext ctx) throws Exception {
                     events.add(0);

testsuite/src/main/java/io/netty/testsuite/transport/socket/SocketConnectionAttemptTest.java

@@ -19,7 +19,7 @@ import io.netty.bootstrap.Bootstrap;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelOption;
 import io.netty.util.internal.SocketUtils;
 import io.netty.util.NetUtil;
@@ -78,7 +78,7 @@ public class SocketConnectionAttemptTest extends AbstractClientSocketTest {
 
     private static void testConnectRefused0(Bootstrap cb, boolean halfClosure) throws Throwable {
         final Promise<Error> errorPromise = GlobalEventExecutor.INSTANCE.newPromise();
-        ChannelHandler handler = new ChannelInboundHandlerAdapter() {
+        ChannelHandler handler = new ChannelInboundHandler() {
             @Override
             public void channelActive(ChannelHandlerContext ctx) throws Exception {
                 errorPromise.setFailure(new AssertionError("should have never been called"));
@@ -142,7 +142,7 @@ public class SocketConnectionAttemptTest extends AbstractClientSocketTest {
         }
     }
 
-    private static class TestHandler extends ChannelInboundHandlerAdapter {
+    private static class TestHandler implements ChannelInboundHandler {
         @Override
         public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
             InternalLoggerFactory.getInstance(

testsuite/src/main/java/io/netty/testsuite/transport/socket/SocketDataReadInitialStateTest.java

@@ -20,7 +20,7 @@ import io.netty.bootstrap.ServerBootstrap;
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.SimpleChannelInboundHandler;
 import org.junit.Test;
@@ -55,7 +55,7 @@ public class SocketDataReadInitialStateTest extends AbstractSocketTest {
             sb.handler(new ChannelInitializer<Channel>() {
                 @Override
                 protected void initChannel(Channel ch) {
-                    ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                    ch.pipeline().addLast(new ChannelInboundHandler() {
                         @Override
                         public void channelRead(ChannelHandlerContext ctx, Object msg) {
                             acceptorReadLatch.countDown();

testsuite/src/main/java/io/netty/testsuite/transport/socket/SocketEchoTest.java

@@ -21,7 +21,7 @@ import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.SimpleChannelInboundHandler;
 import org.junit.Test;
@@ -85,7 +85,7 @@ public class SocketEchoTest extends AbstractSocketTest {
         final EchoHandler ch = new EchoHandler(autoRead);
 
         sb.childHandler(sh);
-        sb.handler(new ChannelInboundHandlerAdapter() {
+        sb.handler(new ChannelInboundHandler() {
             @Override
             public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
                 cause.printStackTrace();

testsuite/src/main/java/io/netty/testsuite/transport/socket/SocketExceptionHandlingTest.java

@@ -20,7 +20,7 @@ import io.netty.bootstrap.ServerBootstrap;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.ChannelPipeline;
@@ -83,7 +83,7 @@ public class SocketExceptionHandlingTest extends AbstractSocketTest {
         }
     }
 
-    private static class BuggyChannelHandler extends ChannelInboundHandlerAdapter {
+    private static class BuggyChannelHandler implements ChannelInboundHandler {
         @Override
         public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
             ReferenceCountUtil.release(msg);
@@ -91,7 +91,7 @@ public class SocketExceptionHandlingTest extends AbstractSocketTest {
         }
     }
 
-    private static class ExceptionHandler extends ChannelInboundHandlerAdapter {
+    private static class ExceptionHandler implements ChannelInboundHandler {
         final AtomicLong count = new AtomicLong();
         /**
          * We expect to get 1 call to {@link #exceptionCaught(ChannelHandlerContext, Throwable)}.

testsuite/src/main/java/io/netty/testsuite/transport/socket/SocketFileRegionTest.java

@@ -22,7 +22,6 @@ import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInboundHandler;
-import io.netty.channel.ChannelInboundHandlerAdapter;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.DefaultFileRegion;
 import io.netty.channel.FileRegion;
@@ -114,7 +113,7 @@ public class SocketFileRegionTest extends AbstractSocketTest {
                 // Just drop the message.
             }
         });
-        cb.handler(new ChannelInboundHandlerAdapter());
+        cb.handler(new ChannelInboundHandler() { });
 
         Channel sc = sb.bind().sync().channel();
         Channel cc = cb.connect(sc.localAddress()).sync().channel();

testsuite/src/main/java/io/netty/testsuite/transport/socket/SocketHalfClosedTest.java

@@ -21,10 +21,9 @@ import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufAllocator;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelConfig;
-import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.RecvByteBufAllocator;
@@ -62,7 +61,7 @@ public class SocketHalfClosedTest extends AbstractSocketTest {
             sb.childHandler(new ChannelInitializer<Channel>() {
                 @Override
                 protected void initChannel(Channel ch) {
-                    ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                    ch.pipeline().addLast(new ChannelInboundHandler() {
                         @Override
                         public void channelActive(ChannelHandlerContext ctx) {
                             ((DuplexChannel) ctx).shutdownOutput();
@@ -82,7 +81,7 @@ public class SocketHalfClosedTest extends AbstractSocketTest {
             cb.handler(new ChannelInitializer<Channel>() {
                 @Override
                 protected void initChannel(Channel ch) {
-                    ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                    ch.pipeline().addLast(new ChannelInboundHandler() {
 
                         @Override
                         public void userEventTriggered(final ChannelHandlerContext ctx, Object evt) {
@@ -142,7 +141,7 @@ public class SocketHalfClosedTest extends AbstractSocketTest {
             sb.childHandler(new ChannelInitializer<Channel>() {
                 @Override
                 protected void initChannel(Channel ch) throws Exception {
-                    ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                    ch.pipeline().addLast(new ChannelInboundHandler() {
                         @Override
                         public void channelActive(ChannelHandlerContext ctx) throws Exception {
                             ByteBuf buf = ctx.alloc().buffer(totalServerBytesWritten);
@@ -163,7 +162,7 @@ public class SocketHalfClosedTest extends AbstractSocketTest {
             cb.handler(new ChannelInitializer<Channel>() {
                 @Override
                 protected void initChannel(Channel ch) throws Exception {
-                    ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                    ch.pipeline().addLast(new ChannelInboundHandler() {
                         private int bytesRead;
 
                         @Override
@@ -441,7 +440,7 @@ public class SocketHalfClosedTest extends AbstractSocketTest {
             sb.childHandler(new ChannelInitializer<Channel>() {
                 @Override
                 protected void initChannel(Channel ch) throws Exception {
-                    ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                    ch.pipeline().addLast(new ChannelInboundHandler() {
                         @Override
                         public void channelActive(ChannelHandlerContext ctx) throws Exception {
                             ByteBuf buf = ctx.alloc().buffer(totalServerBytesWritten);
@@ -461,7 +460,7 @@ public class SocketHalfClosedTest extends AbstractSocketTest {
             cb.handler(new ChannelInitializer<Channel>() {
                 @Override
                 protected void initChannel(Channel ch) throws Exception {
-                    ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                    ch.pipeline().addLast(new ChannelInboundHandler() {
                         private int bytesRead;
 
                         @Override

testsuite/src/main/java/io/netty/testsuite/transport/socket/SocketMultipleConnectTest.java

@@ -19,7 +19,7 @@ import io.netty.bootstrap.Bootstrap;
 import io.netty.bootstrap.ServerBootstrap;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.testsuite.transport.TestsuitePermutation;
 import io.netty.util.NetUtil;
 import org.junit.Test;
@@ -41,10 +41,10 @@ public class SocketMultipleConnectTest extends AbstractSocketTest {
         Channel sc = null;
         Channel cc = null;
         try {
-            sb.childHandler(new ChannelInboundHandlerAdapter());
+            sb.childHandler(new ChannelInboundHandler() { });
             sc = sb.bind(NetUtil.LOCALHOST, 0).syncUninterruptibly().channel();
 
-            cb.handler(new ChannelInboundHandlerAdapter());
+            cb.handler(new ChannelInboundHandler() { });
             cc = cb.register().syncUninterruptibly().channel();
             cc.connect(sc.localAddress()).syncUninterruptibly();
             ChannelFuture connectFuture2 = cc.connect(sc.localAddress()).await();

testsuite/src/main/java/io/netty/testsuite/transport/socket/SocketObjectEchoTest.java

@@ -19,7 +19,7 @@ import io.netty.bootstrap.Bootstrap;
 import io.netty.bootstrap.ServerBootstrap;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelOption;
 import io.netty.handler.codec.serialization.ClassResolvers;
@@ -149,7 +149,7 @@ public class SocketObjectEchoTest extends AbstractSocketTest {
         }
     }
 
-    private static class EchoHandler extends ChannelInboundHandlerAdapter {
+    private static class EchoHandler implements ChannelInboundHandler {
         private final boolean autoRead;
         volatile Channel channel;
         final AtomicReference<Throwable> exception = new AtomicReference<>();

testsuite/src/main/java/io/netty/testsuite/transport/socket/SocketReadPendingTest.java

@@ -23,7 +23,7 @@ import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelConfig;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.RecvByteBufAllocator;
@@ -101,7 +101,7 @@ public class SocketReadPendingTest extends AbstractSocketTest {
         }
     }
 
-    private static final class ReadPendingReadHandler extends ChannelInboundHandlerAdapter {
+    private static final class ReadPendingReadHandler implements ChannelInboundHandler {
         private final AtomicInteger count = new AtomicInteger();
         private final CountDownLatch latch = new CountDownLatch(1);
         private final CountDownLatch latch2 = new CountDownLatch(2);

testsuite/src/main/java/io/netty/testsuite/transport/socket/SocketRstTest.java

@@ -19,7 +19,7 @@ import io.netty.bootstrap.Bootstrap;
 import io.netty.bootstrap.ServerBootstrap;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelOption;
 import org.junit.Test;
@@ -62,7 +62,7 @@ public class SocketRstTest extends AbstractSocketTest {
         cb.handler(new ChannelInitializer<Channel>() {
             @Override
             protected void initChannel(Channel ch) throws Exception {
-                ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                ch.pipeline().addLast(new ChannelInboundHandler() {
                     @Override
                     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
                         throwableRef.compareAndSet(null, cause);
@@ -115,7 +115,7 @@ public class SocketRstTest extends AbstractSocketTest {
         cb.handler(new ChannelInitializer<Channel>() {
             @Override
             protected void initChannel(Channel ch) throws Exception {
-                ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
+                ch.pipeline().addLast(new ChannelInboundHandler() {
                     @Override
                     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
                         throwableRef.compareAndSet(null, cause);

testsuite/src/main/java/io/netty/testsuite/transport/socket/SocketShutdownOutputBySelfTest.java

@@ -20,7 +20,7 @@ import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.SimpleChannelInboundHandler;
 import io.netty.channel.WriteBufferWaterMark;
@@ -216,7 +216,7 @@ public class SocketShutdownOutputBySelfTest extends AbstractClientSocketTest {
         ChannelFuture cf = null;
         try {
             ss.bind(newSocketAddress());
-            cf = cb.option(ChannelOption.SO_LINGER, 1).handler(new ChannelInboundHandlerAdapter())
+            cf = cb.option(ChannelOption.SO_LINGER, 1).handler(new ChannelInboundHandler() { })
                     .connect(ss.getLocalSocketAddress()).sync();
             s = ss.accept();
 

testsuite/src/main/java/io/netty/testsuite/transport/socket/WriteBeforeRegisteredTest.java

@@ -18,7 +18,7 @@ package io.netty.testsuite.transport.socket;
 import io.netty.bootstrap.Bootstrap;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.socket.SocketChannel;
 import org.junit.Test;
 
@@ -42,7 +42,7 @@ public class WriteBeforeRegisteredTest extends AbstractClientSocketTest {
         }
     }
 
-    private static class TestHandler extends ChannelInboundHandlerAdapter {
+    private static class TestHandler implements ChannelInboundHandler {
         @Override
         public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
             cause.printStackTrace();

transport-native-epoll/src/test/java/io/netty/channel/epoll/EpollDomainSocketFdTest.java

@@ -18,10 +18,9 @@ package io.netty.channel.epoll;
 import io.netty.bootstrap.Bootstrap;
 import io.netty.bootstrap.ServerBootstrap;
 import io.netty.channel.Channel;
-import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.unix.DomainSocketReadMode;
 import io.netty.channel.unix.FileDescriptor;
 import io.netty.testsuite.transport.TestsuitePermutation;
@@ -53,7 +52,7 @@ public class EpollDomainSocketFdTest extends AbstractSocketTest {
 
     public void testSendRecvFd(ServerBootstrap sb, Bootstrap cb) throws Throwable {
         final BlockingQueue<Object> queue = new LinkedBlockingQueue<>(1);
-        sb.childHandler(new ChannelInboundHandlerAdapter() {
+        sb.childHandler(new ChannelInboundHandler() {
             @Override
             public void channelActive(ChannelHandlerContext ctx) throws Exception {
                 // Create new channel and obtain a file descriptor from it.
@@ -67,7 +66,7 @@ public class EpollDomainSocketFdTest extends AbstractSocketTest {
                 });
             }
         });
-        cb.handler(new ChannelInboundHandlerAdapter() {
+        cb.handler(new ChannelInboundHandler() {
             @Override
             public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
                 FileDescriptor fd = (FileDescriptor) msg;

transport-native-epoll/src/test/java/io/netty/channel/epoll/EpollReuseAddrTest.java

@@ -22,7 +22,7 @@ import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerAdapter;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.util.NetUtil;
 import io.netty.util.ReferenceCountUtil;
 import io.netty.util.ResourceLeakDetector;
@@ -200,7 +200,7 @@ public class EpollReuseAddrTest {
     }
 
     @ChannelHandler.Sharable
-    private static class ServerSocketTestHandler extends ChannelInboundHandlerAdapter {
+    private static class ServerSocketTestHandler implements ChannelInboundHandler {
         private final AtomicBoolean accepted;
 
         ServerSocketTestHandler(AtomicBoolean accepted) {
@@ -215,7 +215,7 @@ public class EpollReuseAddrTest {
     }
 
     @ChannelHandler.Sharable
-    private static class DatagramSocketTestHandler extends ChannelInboundHandlerAdapter {
+    private static class DatagramSocketTestHandler implements ChannelInboundHandler {
         private final AtomicBoolean received;
 
         DatagramSocketTestHandler(AtomicBoolean received) {

transport-native-epoll/src/test/java/io/netty/channel/epoll/EpollServerSocketChannelConfigTest.java

@@ -16,7 +16,7 @@
 package io.netty.channel.epoll;
 
 import io.netty.bootstrap.ServerBootstrap;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.EventLoopGroup;
 import io.netty.channel.MultithreadEventLoopGroup;
@@ -40,7 +40,7 @@ public class EpollServerSocketChannelConfigTest {
         ServerBootstrap bootstrap = new ServerBootstrap();
         ch = (EpollServerSocketChannel) bootstrap.group(group)
                 .channel(EpollServerSocketChannel.class)
-                .childHandler(new ChannelInboundHandlerAdapter())
+                .childHandler(new ChannelInboundHandler() { })
                 .bind(new InetSocketAddress(0)).syncUninterruptibly().channel();
     }
 

transport-native-epoll/src/test/java/io/netty/channel/epoll/EpollSocketChannelConfigTest.java

@@ -19,7 +19,7 @@ import static org.junit.Assert.*;
 import static org.junit.Assume.*;
 import io.netty.bootstrap.Bootstrap;
 import io.netty.channel.ChannelException;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.EventLoopGroup;
 
@@ -57,7 +57,7 @@ public class EpollSocketChannelConfigTest {
         Bootstrap bootstrap = new Bootstrap();
         ch = (EpollSocketChannel) bootstrap.group(group)
                 .channel(EpollSocketChannel.class)
-                .handler(new ChannelInboundHandlerAdapter())
+                .handler(new ChannelInboundHandler() { })
                 .bind(new InetSocketAddress(0)).syncUninterruptibly().channel();
     }
 

transport-native-epoll/src/test/java/io/netty/channel/epoll/EpollSocketChannelTest.java

@@ -16,7 +16,7 @@
 package io.netty.channel.epoll;
 
 import io.netty.bootstrap.Bootstrap;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.EventLoopGroup;
 import io.netty.channel.MultithreadEventLoopGroup;
@@ -35,7 +35,7 @@ public class EpollSocketChannelTest {
             Bootstrap bootstrap = new Bootstrap();
             EpollSocketChannel ch = (EpollSocketChannel) bootstrap.group(group)
                     .channel(EpollSocketChannel.class)
-                    .handler(new ChannelInboundHandlerAdapter())
+                    .handler(new ChannelInboundHandler() { })
                     .bind(new InetSocketAddress(0)).syncUninterruptibly().channel();
             EpollTcpInfo info = ch.tcpInfo();
             assertTcpInfo0(info);
@@ -53,7 +53,7 @@ public class EpollSocketChannelTest {
             Bootstrap bootstrap = new Bootstrap();
             EpollSocketChannel ch = (EpollSocketChannel) bootstrap.group(group)
                     .channel(EpollSocketChannel.class)
-                    .handler(new ChannelInboundHandlerAdapter())
+                    .handler(new ChannelInboundHandler() { })
                     .bind(new InetSocketAddress(0)).syncUninterruptibly().channel();
             EpollTcpInfo info = new EpollTcpInfo();
             ch.tcpInfo(info);
@@ -111,7 +111,7 @@ public class EpollSocketChannelTest {
             EpollSocketChannel ch = (EpollSocketChannel) bootstrap.group(group)
                     .channel(EpollSocketChannel.class)
                     .option(ChannelOption.SO_LINGER, 10)
-                    .handler(new ChannelInboundHandlerAdapter())
+                    .handler(new ChannelInboundHandler() { })
                     .bind(new InetSocketAddress(0)).syncUninterruptibly().channel();
             ch.close().syncUninterruptibly();
         } finally {

transport-native-epoll/src/test/java/io/netty/channel/epoll/EpollSocketTcpMd5Test.java

@@ -17,7 +17,7 @@ package io.netty.channel.epoll;
 
 import io.netty.bootstrap.Bootstrap;
 import io.netty.bootstrap.ServerBootstrap;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.ConnectTimeoutException;
 import io.netty.channel.EventLoopGroup;
@@ -55,7 +55,7 @@ public class EpollSocketTcpMd5Test {
         ServerBootstrap bootstrap = new ServerBootstrap();
         server = (EpollServerSocketChannel) bootstrap.group(GROUP)
                 .channel(EpollServerSocketChannel.class)
-                .childHandler(new ChannelInboundHandlerAdapter())
+                .childHandler(new ChannelInboundHandler() { })
                 .bind(new InetSocketAddress(NetUtil.LOCALHOST4, 0)).syncUninterruptibly().channel();
     }
 
@@ -76,7 +76,7 @@ public class EpollSocketTcpMd5Test {
         ServerBootstrap bootstrap = new ServerBootstrap();
         EpollServerSocketChannel ch = (EpollServerSocketChannel) bootstrap.group(GROUP)
                 .channel(EpollServerSocketChannel.class)
-                .childHandler(new ChannelInboundHandlerAdapter())
+                .childHandler(new ChannelInboundHandler() { })
                 .bind(new InetSocketAddress(0)).syncUninterruptibly().channel();
 
         ch.config().setOption(EpollChannelOption.TCP_MD5SIG,
@@ -93,7 +93,7 @@ public class EpollSocketTcpMd5Test {
 
         EpollSocketChannel client = (EpollSocketChannel) new Bootstrap().group(GROUP)
                 .channel(EpollSocketChannel.class)
-                .handler(new ChannelInboundHandlerAdapter())
+                .handler(new ChannelInboundHandler() { })
                 .option(EpollChannelOption.TCP_MD5SIG,
                         Collections.singletonMap(NetUtil.LOCALHOST4, BAD_KEY))
                 .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 1000)
@@ -108,7 +108,7 @@ public class EpollSocketTcpMd5Test {
 
         EpollSocketChannel client = (EpollSocketChannel) new Bootstrap().group(GROUP)
                 .channel(EpollSocketChannel.class)
-                .handler(new ChannelInboundHandlerAdapter())
+                .handler(new ChannelInboundHandler() { })
                 .option(EpollChannelOption.TCP_MD5SIG,
                         Collections.singletonMap(NetUtil.LOCALHOST4, SERVER_KEY))
                 .connect(server.localAddress()).syncUninterruptibly().channel();

transport-native-epoll/src/test/java/io/netty/channel/epoll/EpollSpliceTest.java

@@ -23,7 +23,7 @@ import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.EventLoopGroup;
 import io.netty.channel.MultithreadEventLoopGroup;
 import io.netty.channel.SimpleChannelInboundHandler;
@@ -64,7 +64,7 @@ public class EpollSpliceTest {
         ServerBootstrap bs2 = new ServerBootstrap();
         bs2.channel(EpollServerSocketChannel.class);
         bs2.childOption(EpollChannelOption.EPOLL_MODE, EpollMode.LEVEL_TRIGGERED);
-        bs2.group(group).childHandler(new ChannelInboundHandlerAdapter() {
+        bs2.group(group).childHandler(new ChannelInboundHandler() {
             @Override
             public void channelActive(final ChannelHandlerContext ctx) throws Exception {
                 ctx.channel().config().setAutoRead(false);
@@ -72,7 +72,7 @@ public class EpollSpliceTest {
                 bs.option(EpollChannelOption.EPOLL_MODE, EpollMode.LEVEL_TRIGGERED);
 
                 bs.channel(EpollSocketChannel.class);
-                bs.group(ctx.channel().eventLoop()).handler(new ChannelInboundHandlerAdapter() {
+                bs.group(ctx.channel().eventLoop()).handler(new ChannelInboundHandler() {
                     @Override
                     public void channelActive(ChannelHandlerContext context) throws Exception {
                         final EpollSocketChannel ch = (EpollSocketChannel) ctx.channel();
@@ -195,7 +195,7 @@ public class EpollSpliceTest {
         Bootstrap cb = new Bootstrap();
         cb.group(group);
         cb.channel(EpollSocketChannel.class);
-        cb.handler(new ChannelInboundHandlerAdapter());
+        cb.handler(new ChannelInboundHandler() { });
         Channel cc = cb.connect(sc.localAddress()).syncUninterruptibly().channel();
 
         for (int i = 0; i < data.length;) {
@@ -278,7 +278,7 @@ public class EpollSpliceTest {
         }
     }
 
-    private static class SpliceHandler extends ChannelInboundHandlerAdapter {
+    private static class SpliceHandler implements ChannelInboundHandler {
         private final File file;
 
         volatile Channel channel;

transport-native-kqueue/src/test/java/io/netty/channel/kqueue/KQueueChannelConfigTest.java

@@ -17,7 +17,7 @@ package io.netty.channel.kqueue;
 
 import io.netty.bootstrap.Bootstrap;
 import io.netty.channel.ChannelException;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInboundHandler;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.EventLoopGroup;
 import io.netty.channel.MultithreadEventLoopGroup;
@@ -80,7 +80,7 @@ public class KQueueChannelConfigTest {
             KQueueSocketChannel ch = (KQueueSocketChannel) bootstrap.group(group)
                     .channel(KQueueSocketChannel.class)
                     .option(ChannelOption.SO_LINGER, 10)
-                    .handler(new ChannelInboundHandlerAdapter())
+                    .handler(new ChannelInboundHandler() { })
                     .bind(new InetSocketAddress(0)).syncUninterruptibly().channel();
             ch.close().syncUninterruptibly();
         } finally {