[#902] Remove usage of generics for output of Encoder/Decoder to make them more flexible again

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

@@ -47,7 +47,7 @@ import java.util.Map.Entry;
  * @apiviz.landmark
  * @apiviz.has io.netty.handler.codec.http.HttpChunk oneway - - filters out
  */
-public class HttpChunkAggregator extends MessageToMessageDecoder<HttpObject, HttpMessage> {
+public class HttpChunkAggregator extends MessageToMessageDecoder<HttpObject> {
     public static final int DEFAULT_MAX_COMPOSITEBUFFER_COMPONENTS = 1024;
     private static final ByteBuf CONTINUE = Unpooled.copiedBuffer(
             "HTTP/1.1 100 Continue\r\n\r\n", CharsetUtil.US_ASCII);
@@ -110,7 +110,7 @@ public class HttpChunkAggregator extends MessageToMessageDecoder<HttpObject, Htt
     }
 
     @Override
-    protected HttpMessage decode(ChannelHandlerContext ctx, HttpObject msg) throws Exception {
+    protected Object decode(ChannelHandlerContext ctx, HttpObject msg) throws Exception {
         HttpMessage currentMessage = this.currentMessage;
 
         if (msg instanceof HttpMessage) {

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

@@ -40,7 +40,7 @@ import io.netty.handler.codec.MessageToMessageDecoder;
  * so that this handler can intercept HTTP requests after {@link HttpMessageDecoder}
  * converts {@link ByteBuf}s into HTTP requests.
  */
-public abstract class HttpContentDecoder extends MessageToMessageDecoder<Object, Object> {
+public abstract class HttpContentDecoder extends MessageToMessageDecoder<Object> {
 
     private EmbeddedByteChannel decoder;
 

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

@@ -46,7 +46,7 @@ import java.util.Queue;
  * so that this handler can intercept HTTP responses before {@link HttpMessageEncoder}
  * converts them into {@link ByteBuf}s.
  */
-public abstract class HttpContentEncoder extends MessageToMessageCodec<HttpMessage, HttpMessage, Object, Object> {
+public abstract class HttpContentEncoder extends MessageToMessageCodec<HttpMessage, Object> {
 
     private final Queue<String> acceptEncodingQueue = new ArrayDeque<String>();
     private EmbeddedByteChannel encoder;
@@ -61,7 +61,7 @@ public abstract class HttpContentEncoder extends MessageToMessageCodec<HttpMessa
     }
 
     @Override
-    protected HttpMessage decode(ChannelHandlerContext ctx, HttpMessage msg)
+    protected Object decode(ChannelHandlerContext ctx, HttpMessage msg)
             throws Exception {
         String acceptedEncoding = msg.getHeader(HttpHeaders.Names.ACCEPT_ENCODING);
         if (acceptedEncoding == null) {

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

@@ -98,7 +98,7 @@ import java.util.List;
  * implement all abstract methods properly.
  * @apiviz.landmark
  */
-public abstract class HttpMessageDecoder extends ReplayingDecoder<Object, HttpMessageDecoder.State> {
+public abstract class HttpMessageDecoder extends ReplayingDecoder<HttpMessageDecoder.State> {
 
     private final int maxInitialLineLength;
     private final int maxHeaderSize;

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/WebSocket00FrameDecoder.java

@@ -29,7 +29,7 @@ import io.netty.handler.codec.TooLongFrameException;
  * @apiviz.landmark
  * @apiviz.uses io.netty.handler.codec.http.websocket.WebSocketFrame
  */
-public class WebSocket00FrameDecoder extends ReplayingDecoder<WebSocketFrame, Void> {
+public class WebSocket00FrameDecoder extends ReplayingDecoder<Void> {
 
     static final int DEFAULT_MAX_FRAME_SIZE = 16384;
 
@@ -52,7 +52,7 @@ public class WebSocket00FrameDecoder extends ReplayingDecoder<WebSocketFrame, Vo
     }
 
     @Override
-    public WebSocketFrame decode(ChannelHandlerContext ctx, ByteBuf in) throws Exception {
+    public Object decode(ChannelHandlerContext ctx, ByteBuf in) throws Exception {
         // Discard all data received if closing handshake was received before.
         if (receivedClosingHandshake) {
             in.skipBytes(actualReadableBytes());

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/WebSocket08FrameDecoder.java

@@ -67,7 +67,7 @@ import io.netty.logging.InternalLoggerFactory;
  * Decodes a web socket frame from wire protocol version 8 format. This code was forked from <a
  * href="https://github.com/joewalnes/webbit">webbit</a> and modified.
  */
-public class WebSocket08FrameDecoder extends ReplayingDecoder<WebSocketFrame, WebSocket08FrameDecoder.State> {
+public class WebSocket08FrameDecoder extends ReplayingDecoder<WebSocket08FrameDecoder.State> {
 
     private static final InternalLogger logger = InternalLoggerFactory.getInstance(WebSocket08FrameDecoder.class);
 
@@ -118,7 +118,7 @@ public class WebSocket08FrameDecoder extends ReplayingDecoder<WebSocketFrame, We
     }
 
     @Override
-    public WebSocketFrame decode(
+    public Object decode(
             ChannelHandlerContext ctx, ByteBuf in) throws Exception {
 
         // Discard all data received if closing handshake was received before.

codec-http/src/main/java/io/netty/handler/codec/spdy/SpdyFrameDecoder.java

@@ -25,7 +25,7 @@ import io.netty.handler.codec.TooLongFrameException;
 /**
  * Decodes {@link ByteBuf}s into SPDY Data and Control Frames.
  */
-public class SpdyFrameDecoder extends ByteToMessageDecoder<Object> {
+public class SpdyFrameDecoder extends ByteToMessageDecoder {
 
     private final int spdyVersion;
     private final int maxChunkSize;

codec-http/src/main/java/io/netty/handler/codec/spdy/SpdyFrameEncoder.java

@@ -31,7 +31,7 @@ import static io.netty.handler.codec.spdy.SpdyCodecUtil.*;
 /**
  * Encodes a SPDY Data or Control Frame into a {@link ByteBuf}.
  */
-public class SpdyFrameEncoder extends MessageToByteEncoder<Object> {
+public class SpdyFrameEncoder extends MessageToByteEncoder {
 
     private final int version;
     private volatile boolean finished;

codec-http/src/main/java/io/netty/handler/codec/spdy/SpdyHttpDecoder.java

@@ -37,7 +37,7 @@ import java.util.Map;
  * Decodes {@link SpdySynStreamFrame}s, {@link SpdySynReplyFrame}s,
  * and {@link SpdyDataFrame}s into {@link HttpRequest}s and {@link HttpResponse}s.
  */
-public class SpdyHttpDecoder extends MessageToMessageDecoder<Object, HttpMessage> {
+public class SpdyHttpDecoder extends MessageToMessageDecoder<Object> {
 
     private final int spdyVersion;
     private final int maxContentLength;
@@ -67,7 +67,7 @@ public class SpdyHttpDecoder extends MessageToMessageDecoder<Object, HttpMessage
     }
 
     @Override
-    public HttpMessage decode(ChannelHandlerContext ctx, Object msg) throws Exception {
+    public Object decode(ChannelHandlerContext ctx, Object msg) throws Exception {
         if (msg instanceof SpdySynStreamFrame) {
 
             // HTTP requests/responses are mapped one-to-one to SPDY streams.

codec-http/src/main/java/io/netty/handler/codec/spdy/SpdyHttpEncoder.java

@@ -119,7 +119,7 @@ import java.util.Map;
  * All pushed resources should be sent before sending the response
  * that corresponds to the initial request.
  */
-public class SpdyHttpEncoder extends MessageToMessageEncoder<Object, Object> {
+public class SpdyHttpEncoder extends MessageToMessageEncoder<Object> {
 
     private final int spdyVersion;
     private volatile int currentStreamId;

codec-http/src/main/java/io/netty/handler/codec/spdy/SpdyHttpResponseStreamIdHandler.java

@@ -29,7 +29,7 @@ import io.netty.handler.codec.http.HttpResponse;
  * for HTTP.
  */
 public class SpdyHttpResponseStreamIdHandler extends
-        MessageToMessageCodec<Object, Object, HttpMessage, HttpMessage> {
+        MessageToMessageCodec<Object, HttpMessage> {
     private static final Integer NO_ID = -1;
     private final Queue<Integer> ids = new LinkedList<Integer>();
 
@@ -38,7 +38,7 @@ public class SpdyHttpResponseStreamIdHandler extends
     }
 
     @Override
-    protected HttpMessage encode(ChannelHandlerContext ctx, HttpMessage msg) throws Exception {
+    protected Object encode(ChannelHandlerContext ctx, HttpMessage msg) throws Exception {
         Integer id = ids.poll();
         if (id != null && id.intValue() != NO_ID && !msg.containsHeader(SpdyHttpHeaders.Names.STREAM_ID)) {
             SpdyHttpHeaders.setStreamId(msg, id);

codec-socks/src/main/java/io/netty/handler/codec/socks/SocksAuthRequestDecoder.java

@@ -24,7 +24,7 @@ import io.netty.util.CharsetUtil;
  * Decodes {@link ByteBuf}s into {@link SocksAuthRequest}.
  * Before returning SocksRequest decoder removes itself from pipeline.
  */
-public class SocksAuthRequestDecoder extends ReplayingDecoder<SocksRequest, SocksAuthRequestDecoder.State> {
+public class SocksAuthRequestDecoder extends ReplayingDecoder<SocksAuthRequestDecoder.State> {
     private static final String name = "SOCKS_AUTH_REQUEST_DECODER";
 
     public static String getName() {
@@ -42,7 +42,7 @@ public class SocksAuthRequestDecoder extends ReplayingDecoder<SocksRequest, Sock
     }
 
     @Override
-    public SocksRequest decode(ChannelHandlerContext ctx, ByteBuf byteBuf) throws Exception {
+    public Object decode(ChannelHandlerContext ctx, ByteBuf byteBuf) throws Exception {
         switch (state()) {
             case CHECK_PROTOCOL_VERSION: {
                 version = SocksMessage.SubnegotiationVersion.fromByte(byteBuf.readByte());

codec-socks/src/main/java/io/netty/handler/codec/socks/SocksAuthResponseDecoder.java

@@ -23,7 +23,7 @@ import io.netty.handler.codec.ReplayingDecoder;
  * Decodes {@link ByteBuf}s into {@link SocksAuthResponse}.
  * Before returning SocksResponse decoder removes itself from pipeline.
  */
-public class SocksAuthResponseDecoder extends ReplayingDecoder<SocksResponse, SocksAuthResponseDecoder.State> {
+public class SocksAuthResponseDecoder extends ReplayingDecoder<SocksAuthResponseDecoder.State> {
     private static final String name = "SOCKS_AUTH_RESPONSE_DECODER";
 
     public static String getName() {
@@ -39,7 +39,7 @@ public class SocksAuthResponseDecoder extends ReplayingDecoder<SocksResponse, So
     }
 
     @Override
-    public SocksResponse decode(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf) throws Exception {
+    public Object decode(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf) throws Exception {
         switch (state()) {
             case CHECK_PROTOCOL_VERSION: {
                 version = SocksMessage.SubnegotiationVersion.fromByte(byteBuf.readByte());

codec-socks/src/main/java/io/netty/handler/codec/socks/SocksCmdRequestDecoder.java

@@ -24,7 +24,7 @@ import io.netty.util.CharsetUtil;
  * Decodes {@link ByteBuf}s into {@link SocksCmdRequest}.
  * Before returning SocksRequest decoder removes itself from pipeline.
  */
-public class SocksCmdRequestDecoder extends ReplayingDecoder<SocksRequest, SocksCmdRequestDecoder.State> {
+public class SocksCmdRequestDecoder extends ReplayingDecoder<SocksCmdRequestDecoder.State> {
     private static final String name = "SOCKS_CMD_REQUEST_DECODER";
 
     public static String getName() {
@@ -45,8 +45,7 @@ public class SocksCmdRequestDecoder extends ReplayingDecoder<SocksRequest, Socks
     }
 
     @Override
-    public SocksRequest decode(ChannelHandlerContext ctx, ByteBuf byteBuf) throws Exception {
+    public Object decode(ChannelHandlerContext ctx, ByteBuf byteBuf) throws Exception {
-
         switch (state()) {
             case CHECK_PROTOCOL_VERSION: {
                 version = SocksMessage.ProtocolVersion.fromByte(byteBuf.readByte());

codec-socks/src/main/java/io/netty/handler/codec/socks/SocksCmdResponseDecoder.java

@@ -24,7 +24,7 @@ import io.netty.util.CharsetUtil;
  * Decodes {@link ByteBuf}s into {@link SocksCmdResponse}.
  * Before returning SocksResponse decoder removes itself from pipeline.
  */
-public class SocksCmdResponseDecoder extends ReplayingDecoder<SocksResponse, SocksCmdResponseDecoder.State> {
+public class SocksCmdResponseDecoder extends ReplayingDecoder<SocksCmdResponseDecoder.State> {
     private static final String name = "SOCKS_CMD_RESPONSE_DECODER";
 
     public static String getName() {
@@ -45,7 +45,7 @@ public class SocksCmdResponseDecoder extends ReplayingDecoder<SocksResponse, Soc
     }
 
     @Override
-    public SocksResponse decode(ChannelHandlerContext ctx, ByteBuf byteBuf) throws Exception {
+    public Object decode(ChannelHandlerContext ctx, ByteBuf byteBuf) throws Exception {
 
         switch (state()) {
             case CHECK_PROTOCOL_VERSION: {

codec-socks/src/main/java/io/netty/handler/codec/socks/SocksInitRequestDecoder.java

@@ -26,7 +26,7 @@ import java.util.List;
  * Decodes {@link ByteBuf}s into {@link SocksInitRequest}.
  * Before returning SocksRequest decoder removes itself from pipeline.
  */
-public class SocksInitRequestDecoder extends ReplayingDecoder<SocksRequest, SocksInitRequestDecoder.State> {
+public class SocksInitRequestDecoder extends ReplayingDecoder<SocksInitRequestDecoder.State> {
     private static final String name = "SOCKS_INIT_REQUEST_DECODER";
 
     public static String getName() {
@@ -43,7 +43,7 @@ public class SocksInitRequestDecoder extends ReplayingDecoder<SocksRequest, Sock
     }
 
     @Override
-    public SocksRequest decode(ChannelHandlerContext ctx, ByteBuf byteBuf) throws Exception {
+    public Object decode(ChannelHandlerContext ctx, ByteBuf byteBuf) throws Exception {
         switch (state()) {
             case CHECK_PROTOCOL_VERSION: {
                 version = SocksMessage.ProtocolVersion.fromByte(byteBuf.readByte());

codec-socks/src/main/java/io/netty/handler/codec/socks/SocksInitResponseDecoder.java

@@ -23,7 +23,7 @@ import io.netty.handler.codec.ReplayingDecoder;
  * Decodes {@link ByteBuf}s into {@link SocksInitResponse}.
  * Before returning SocksResponse decoder removes itself from pipeline.
  */
-public class SocksInitResponseDecoder extends ReplayingDecoder<SocksResponse, SocksInitResponseDecoder.State> {
+public class SocksInitResponseDecoder extends ReplayingDecoder<SocksInitResponseDecoder.State> {
     private static final String name = "SOCKS_INIT_RESPONSE_DECODER";
 
     public static String getName() {

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

@@ -24,36 +24,35 @@ import io.netty.channel.ChannelInboundByteHandler;
 import io.netty.channel.ChannelOutboundMessageHandler;
 import io.netty.channel.ChannelPromise;
 
-public abstract class ByteToMessageCodec<INBOUND_OUT, OUTBOUND_IN>
+public abstract class ByteToMessageCodec<I> extends ChannelHandlerAdapter
-        extends ChannelHandlerAdapter
+        implements ChannelInboundByteHandler, ChannelOutboundMessageHandler<I> {
-        implements ChannelInboundByteHandler, ChannelOutboundMessageHandler<OUTBOUND_IN> {
 
     private final Class<?>[] encodableMessageTypes;
-    private final MessageToByteEncoder<OUTBOUND_IN> encoder;
+    private final MessageToByteEncoder<I> encoder;
-    private final ByteToMessageDecoder<INBOUND_OUT> decoder;
+    private final ByteToMessageDecoder decoder;
 
     protected ByteToMessageCodec(Class<?>... encodableMessageTypes) {
         this.encodableMessageTypes = encodableMessageTypes;
-        encoder = new MessageToByteEncoder<OUTBOUND_IN>() {
+        encoder = new MessageToByteEncoder<I>() {
             @Override
             public boolean isEncodable(Object msg) throws Exception {
                 return ByteToMessageCodec.this.isEncodable(msg);
             }
 
             @Override
-            protected void encode(ChannelHandlerContext ctx, OUTBOUND_IN msg, ByteBuf out) throws Exception {
+            protected void encode(ChannelHandlerContext ctx, I msg, ByteBuf out) throws Exception {
                 ByteToMessageCodec.this.encode(ctx, msg, out);
             }
         };
 
-        decoder = new ByteToMessageDecoder<INBOUND_OUT>() {
+        decoder = new ByteToMessageDecoder() {
             @Override
-            public INBOUND_OUT decode(ChannelHandlerContext ctx, ByteBuf in) throws Exception {
+            public Object decode(ChannelHandlerContext ctx, ByteBuf in) throws Exception {
                 return ByteToMessageCodec.this.decode(ctx, in);
             }
 
             @Override
-            protected INBOUND_OUT decodeLast(ChannelHandlerContext ctx, ByteBuf in) throws Exception {
+            protected Object decodeLast(ChannelHandlerContext ctx, ByteBuf in) throws Exception {
                 return ByteToMessageCodec.this.decodeLast(ctx, in);
             }
         };
@@ -80,7 +79,7 @@ public abstract class ByteToMessageCodec<INBOUND_OUT, OUTBOUND_IN>
     }
 
     @Override
-    public MessageBuf<OUTBOUND_IN> newOutboundBuffer(ChannelHandlerContext ctx) throws Exception {
+    public MessageBuf<I> newOutboundBuffer(ChannelHandlerContext ctx) throws Exception {
         return encoder.newOutboundBuffer(ctx);
     }
 
@@ -103,9 +102,9 @@ public abstract class ByteToMessageCodec<INBOUND_OUT, OUTBOUND_IN>
         return ChannelHandlerUtil.acceptMessage(encodableMessageTypes, msg);
     }
 
-    protected abstract void encode(ChannelHandlerContext ctx, OUTBOUND_IN msg, ByteBuf out) throws Exception;
+    protected abstract void encode(ChannelHandlerContext ctx, I msg, ByteBuf out) throws Exception;
-    protected abstract INBOUND_OUT decode(ChannelHandlerContext ctx, ByteBuf in) throws Exception;
+    protected abstract Object decode(ChannelHandlerContext ctx, ByteBuf in) throws Exception;
-    protected INBOUND_OUT decodeLast(ChannelHandlerContext ctx, ByteBuf in) throws Exception {
+    protected Object decodeLast(ChannelHandlerContext ctx, ByteBuf in) throws Exception {
         return decode(ctx, in);
     }
 }

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

@@ -30,16 +30,16 @@ import io.netty.channel.ChannelPipeline;
  * the input {@link ByteBuf} and create a new {@link ByteBuf}.
  *
  * <pre>
- *     public class SquareDecoder extends {@link ByteToMessageDecoder}&lt;{@link ByteBuf}&gt; {
+ *     public class SquareDecoder extends {@link ByteToMessageDecoder} {
  *         {@code @Override}
- *         public {@link ByteBuf} decode({@link ChannelHandlerContext} ctx, {@link ByteBuf} in)
+ *         public {@link Object} decode({@link ChannelHandlerContext} ctx, {@link ByteBuf} in)
  *                 throws {@link Exception} {
  *             return in.readBytes(in.readableBytes());
  *         }
  *     }
  * </pre>
  */
-public abstract class ByteToMessageDecoder<O>
+public abstract class ByteToMessageDecoder
     extends ChannelInboundHandlerAdapter implements ChannelInboundByteHandler {
 
     private ChannelHandlerContext ctx;
@@ -94,7 +94,7 @@ public abstract class ByteToMessageDecoder<O>
         while (in.readable()) {
             try {
                 int oldInputLength = in.readableBytes();
-                O o = decode(ctx, in);
+                Object o = decode(ctx, in);
                 if (o == null) {
                     if (oldInputLength == in.readableBytes()) {
                         break;
@@ -167,7 +167,7 @@ public abstract class ByteToMessageDecoder<O>
      *                      there was not enough data left in the {@link ByteBuf} to decode.
      * @throws Exception    is thrown if an error accour
      */
-    protected abstract O decode(ChannelHandlerContext ctx, ByteBuf in) throws Exception;
+    protected abstract Object decode(ChannelHandlerContext ctx, ByteBuf in) throws Exception;
 
     /**
      * Is called one last time when the {@link ChannelHandlerContext} goes in-active. Which means the
@@ -176,7 +176,7 @@ public abstract class ByteToMessageDecoder<O>
      * By default this will just call {@link #decode(ChannelHandlerContext, ByteBuf)} but sub-classes may
      * override this for some special cleanup operation.
      */
-    protected O decodeLast(ChannelHandlerContext ctx, ByteBuf in) throws Exception {
+    protected Object decodeLast(ChannelHandlerContext ctx, ByteBuf in) throws Exception {
         return decode(ctx, in);
     }
 }

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

@@ -54,7 +54,7 @@ import io.netty.channel.ChannelHandlerContext;
  * </pre>
  * @apiviz.uses io.netty.handler.codec.Delimiters - - useful
  */
-public class DelimiterBasedFrameDecoder extends ByteToMessageDecoder<Object> {
+public class DelimiterBasedFrameDecoder extends ByteToMessageDecoder {
 
     private final ByteBuf[] delimiters;
     private final int maxFrameLength;

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

@@ -34,7 +34,7 @@ import io.netty.channel.ChannelHandlerContext;
  * +-----+-----+-----+
  * </pre>
  */
-public class FixedLengthFrameDecoder extends ByteToMessageDecoder<Object> {
+public class FixedLengthFrameDecoder extends ByteToMessageDecoder {
 
     private final int frameLength;
     private final boolean allocateFullBuffer;

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

@@ -179,7 +179,7 @@ import io.netty.handler.codec.serialization.ObjectDecoder;
  * </pre>
  * @see LengthFieldPrepender
  */
-public class LengthFieldBasedFrameDecoder extends ByteToMessageDecoder<Object> {
+public class LengthFieldBasedFrameDecoder extends ByteToMessageDecoder {
 
     private final int maxFrameLength;
     private final int lengthFieldOffset;

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

@@ -24,7 +24,7 @@ import io.netty.channel.ChannelHandlerContext;
  * Both {@code "\n"} and {@code "\r\n"} are handled.
  * For a more general delimiter-based decoder, see {@link DelimiterBasedFrameDecoder}.
  */
-public class LineBasedFrameDecoder extends ByteToMessageDecoder<ByteBuf> {
+public class LineBasedFrameDecoder extends ByteToMessageDecoder {
 
     /** Maximum length of a frame we're willing to decode.  */
     private final int maxLength;
@@ -67,8 +67,7 @@ public class LineBasedFrameDecoder extends ByteToMessageDecoder<ByteBuf> {
     }
 
     @Override
-    protected ByteBuf decode(ChannelHandlerContext ctx, ByteBuf buffer) throws Exception {
+    protected Object decode(ChannelHandlerContext ctx, ByteBuf buffer) throws Exception {
-
         final int eol = findEndOfLine(buffer);
         if (eol != -1) {
             final ByteBuf frame;

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

@@ -48,20 +48,20 @@ import io.netty.channel.ChannelPromise;
  *     }
  * </pre>
  */
-public abstract class MessageToMessageCodec<INBOUND_IN, INBOUND_OUT, OUTBOUND_IN, OUTBOUND_OUT>
+public abstract class MessageToMessageCodec<INBOUND_IN, OUTBOUND_IN>
         extends ChannelHandlerAdapter
         implements ChannelInboundMessageHandler<INBOUND_IN>,
                    ChannelOutboundMessageHandler<OUTBOUND_IN> {
 
-    private final MessageToMessageEncoder<OUTBOUND_IN, OUTBOUND_OUT> encoder =
+    private final MessageToMessageEncoder<OUTBOUND_IN> encoder =
-            new MessageToMessageEncoder<OUTBOUND_IN, OUTBOUND_OUT>() {
+            new MessageToMessageEncoder<OUTBOUND_IN>() {
         @Override
         public boolean isEncodable(Object msg) throws Exception {
             return MessageToMessageCodec.this.isEncodable(msg);
         }
 
         @Override
-        public OUTBOUND_OUT encode(ChannelHandlerContext ctx, OUTBOUND_IN msg) throws Exception {
+        public Object encode(ChannelHandlerContext ctx, OUTBOUND_IN msg) throws Exception {
             return MessageToMessageCodec.this.encode(ctx, msg);
         }
 
@@ -71,15 +71,15 @@ public abstract class MessageToMessageCodec<INBOUND_IN, INBOUND_OUT, OUTBOUND_IN
         }
     };
 
-    private final MessageToMessageDecoder<INBOUND_IN, INBOUND_OUT> decoder =
+    private final MessageToMessageDecoder<INBOUND_IN> decoder =
-            new MessageToMessageDecoder<INBOUND_IN, INBOUND_OUT>() {
+            new MessageToMessageDecoder<INBOUND_IN>() {
         @Override
         public boolean isDecodable(Object msg) throws Exception {
             return MessageToMessageCodec.this.isDecodable(msg);
         }
 
         @Override
-        public INBOUND_OUT decode(ChannelHandlerContext ctx, INBOUND_IN msg) throws Exception {
+        public Object decode(ChannelHandlerContext ctx, INBOUND_IN msg) throws Exception {
             return MessageToMessageCodec.this.decode(ctx, msg);
         }
 
@@ -151,8 +151,8 @@ public abstract class MessageToMessageCodec<INBOUND_IN, INBOUND_OUT, OUTBOUND_IN
         return ChannelHandlerUtil.acceptMessage(acceptedOutboundMsgTypes, msg);
     }
 
-    protected abstract OUTBOUND_OUT encode(ChannelHandlerContext ctx, OUTBOUND_IN msg) throws Exception;
+    protected abstract Object encode(ChannelHandlerContext ctx, OUTBOUND_IN msg) throws Exception;
-    protected abstract INBOUND_OUT decode(ChannelHandlerContext ctx, INBOUND_IN msg) throws Exception;
+    protected abstract Object decode(ChannelHandlerContext ctx, INBOUND_IN msg) throws Exception;
 
     protected void freeInboundMessage(INBOUND_IN msg) throws Exception {
         ChannelHandlerUtil.freeMessage(msg);

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

@@ -31,13 +31,13 @@ import io.netty.channel.ChannelPipeline;
  *
  * <pre>
  *     public class StringToIntegerDecoder extends
- *             {@link MessageToMessageDecoder}&lt;{@link String},{@link Integer}&gt; {
+ *             {@link MessageToMessageDecoder}&lt;{@link String}&gt; {
  *         public StringToIntegerDecoder() {
  *             super(String.class);
  *         }
  *
  *         {@code @Override}
- *         public {@link Integer} decode({@link ChannelHandlerContext} ctx, {@link String} message)
+ *         public {@link Object} decode({@link ChannelHandlerContext} ctx, {@link String} message)
  *                 throws {@link Exception} {
  *             return message.length());
  *         }
@@ -45,7 +45,7 @@ import io.netty.channel.ChannelPipeline;
  * </pre>
  *
  */
-public abstract class MessageToMessageDecoder<I, O>
+public abstract class MessageToMessageDecoder<I>
         extends ChannelInboundHandlerAdapter implements ChannelInboundMessageHandler<I> {
 
     private final Class<?>[] acceptedMsgTypes;
@@ -84,7 +84,7 @@ public abstract class MessageToMessageDecoder<I, O>
                 I imsg = (I) msg;
                 boolean free = true;
                 try {
-                    O omsg = decode(ctx, imsg);
+                    Object omsg = decode(ctx, imsg);
                     if (omsg == null) {
                         // Decoder consumed a message but returned null.
                         // Probably it needs more messages because it's an aggregator.
@@ -131,7 +131,7 @@ public abstract class MessageToMessageDecoder<I, O>
      *                      needs to do some kind of aggragation
      * @throws Exception    is thrown if an error accour
      */
-    protected abstract O decode(ChannelHandlerContext ctx, I msg) throws Exception;
+    protected abstract Object decode(ChannelHandlerContext ctx, I msg) throws Exception;
 
     /**
      * Is called after a message was processed via {@link #decode(ChannelHandlerContext, Object)} to free

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

@@ -31,13 +31,13 @@ import io.netty.channel.PartialFlushException;
  *
  * <pre>
  *     public class IntegerToStringEncoder extends
- *             {@link MessageToMessageEncoder}&lt;{@link Integer},{@link String}&gt; {
+ *             {@link MessageToMessageEncoder}&lt;{@link Integer}&gt; {
  *         public StringToIntegerDecoder() {
  *             super(String.class);
  *         }
  *
  *         {@code @Override}
- *         public {@link String} encode({@link ChannelHandlerContext} ctx, {@link Integer} message)
+ *         public {@link Object} encode({@link ChannelHandlerContext} ctx, {@link Integer} message)
  *                 throws {@link Exception} {
  *             return message.toString();
  *         }
@@ -45,7 +45,7 @@ import io.netty.channel.PartialFlushException;
  * </pre>
  *
  */
-public abstract class MessageToMessageEncoder<I, O> extends ChannelOutboundMessageHandlerAdapter<I> {
+public abstract class MessageToMessageEncoder<I> extends ChannelOutboundMessageHandlerAdapter<I> {
 
     private final Class<?>[] acceptedMsgTypes;
 
@@ -78,7 +78,7 @@ public abstract class MessageToMessageEncoder<I, O> extends ChannelOutboundMessa
                 I imsg = (I) msg;
                 boolean free = true;
                 try {
-                    O omsg = encode(ctx, imsg);
+                    Object omsg = encode(ctx, imsg);
                     if (omsg == null) {
                         // encode() might be waiting for more inbound messages to generate
                         // an aggregated message - keep polling.
@@ -130,7 +130,7 @@ public abstract class MessageToMessageEncoder<I, O> extends ChannelOutboundMessa
      *                      needs to do some kind of aggragation
      * @throws Exception    is thrown if an error accour
      */
-    protected abstract O encode(ChannelHandlerContext ctx, I msg) throws Exception;
+    protected abstract Object encode(ChannelHandlerContext ctx, I msg) throws Exception;
 
     /**
      * Is called after a message was processed via {@link #encode(ChannelHandlerContext, Object)} to free

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

@@ -167,7 +167,7 @@ import io.netty.util.internal.Signal;
  * }
  *
  * public class IntegerHeaderFrameDecoder
- *      extends {@link ReplayingDecoder}&lt;{@link ByteBuf}, <strong>MyDecoderState</strong>&gt; {
+ *      extends {@link ReplayingDecoder}&lt;<strong>MyDecoderState</strong>&gt; {
  *
  *   private int length;
  *
@@ -177,7 +177,7 @@ import io.netty.util.internal.Signal;
  *   }
  *
  *   {@code @Override}
- *   protected {@link ByteBuf} decode({@link ChannelHandlerContext} ctx,
+ *   protected {@link Object} decode({@link ChannelHandlerContext} ctx,
  *                           {@link ByteBuf} in) throws Exception {
  *     switch (state()) {
  *     case READ_LENGTH:
@@ -199,13 +199,13 @@ import io.netty.util.internal.Signal;
  * An alternative way to manage the decoder state is to manage it by yourself.
  * <pre>
  * public class IntegerHeaderFrameDecoder
- *      extends {@link ReplayingDecoder}&lt;{@link ByteBuf},<strong>{@link Void}</strong>&gt; {
+ *      extends {@link ReplayingDecoder}&lt;<strong>{@link Void}</strong>&gt; {
  *
  *   <strong>private boolean readLength;</strong>
  *   private int length;
  *
  *   {@code @Override}
- *   protected {@link ByteBuf} decode({@link ChannelHandlerContext} ctx,
+ *   protected {@link Object} decode({@link ChannelHandlerContext} ctx,
  *                           {@link ByteBuf} in) throws Exception {
  *     if (!readLength) {
  *       length = buf.readInt();
@@ -233,7 +233,7 @@ import io.netty.util.internal.Signal;
  * {@link ChannelPipeline#replace(ChannelHandler, String, ChannelHandler)}, but
  * some additional steps are required:
  * <pre>
- * public class FirstDecoder extends {@link ReplayingDecoder}&lt;{@link Object}, {@link Void}&gt; {
+ * public class FirstDecoder extends {@link ReplayingDecoder}&lt;{@link Void}&gt; {
  *
  *     {@code @Override}
  *     protected Object decode({@link ChannelHandlerContext} ctx,
@@ -264,7 +264,7 @@ import io.netty.util.internal.Signal;
  * @apiviz.landmark
  * @apiviz.has io.netty.handler.codec.UnreplayableOperationException oneway - - throws
  */
-public abstract class ReplayingDecoder<O, S> extends ByteToMessageDecoder<O> {
+public abstract class ReplayingDecoder<S> extends ByteToMessageDecoder {
 
     static final Signal REPLAY = new Signal(ReplayingDecoder.class.getName() + ".REPLAY");
 

codec/src/main/java/io/netty/handler/codec/base64/Base64Decoder.java

@@ -44,7 +44,7 @@ import io.netty.handler.codec.MessageToMessageDecoder;
  * @apiviz.uses io.netty.handler.codec.base64.Base64
  */
 @Sharable
-public class Base64Decoder extends MessageToMessageDecoder<ByteBuf, ByteBuf> {
+public class Base64Decoder extends MessageToMessageDecoder<ByteBuf> {
 
     private final Base64Dialect dialect;
 
@@ -62,7 +62,7 @@ public class Base64Decoder extends MessageToMessageDecoder<ByteBuf, ByteBuf> {
     }
 
     @Override
-    protected ByteBuf decode(ChannelHandlerContext ctx, ByteBuf msg) throws Exception {
+    protected Object decode(ChannelHandlerContext ctx, ByteBuf msg) throws Exception {
         return Base64.decode(msg, msg.readerIndex(), msg.readableBytes(), dialect);
     }
 }

codec/src/main/java/io/netty/handler/codec/base64/Base64Encoder.java

@@ -40,7 +40,7 @@ import io.netty.handler.codec.MessageToMessageEncoder;
  * @apiviz.uses io.netty.handler.codec.base64.Base64
  */
 @Sharable
-public class Base64Encoder extends MessageToMessageEncoder<ByteBuf, ByteBuf> {
+public class Base64Encoder extends MessageToMessageEncoder<ByteBuf> {
 
     private final boolean breakLines;
     private final Base64Dialect dialect;
@@ -65,7 +65,7 @@ public class Base64Encoder extends MessageToMessageEncoder<ByteBuf, ByteBuf> {
     }
 
     @Override
-    protected ByteBuf encode(ChannelHandlerContext ctx,
+    protected Object encode(ChannelHandlerContext ctx,
             ByteBuf msg) throws Exception {
         return Base64.encode(msg, msg.readerIndex(), msg.readableBytes(), breakLines, dialect);
     }

codec/src/main/java/io/netty/handler/codec/bytes/ByteArrayDecoder.java

@@ -46,14 +46,14 @@ import io.netty.handler.codec.MessageToMessageDecoder;
  * }
  * </pre>
  */
-public class ByteArrayDecoder extends MessageToMessageDecoder<ByteBuf, byte[]> {
+public class ByteArrayDecoder extends MessageToMessageDecoder<ByteBuf> {
 
     public ByteArrayDecoder() {
         super(ByteBuf.class);
     }
 
     @Override
-    protected byte[] decode(ChannelHandlerContext ctx, ByteBuf msg) throws Exception {
+    protected Object decode(ChannelHandlerContext ctx, ByteBuf msg) throws Exception {
         byte[] array;
         if (msg.hasArray()) {
             if (msg.arrayOffset() == 0 && msg.readableBytes() == msg.capacity()) {

codec/src/main/java/io/netty/handler/codec/bytes/ByteArrayEncoder.java

@@ -48,7 +48,7 @@ import io.netty.handler.codec.MessageToMessageEncoder;
  * }
  * </pre>
  */
-public class ByteArrayEncoder extends MessageToMessageEncoder<byte[], ByteBuf> {
+public class ByteArrayEncoder extends MessageToMessageEncoder<byte[]> {
 
     public ByteArrayEncoder() {
         super(byte[].class);

codec/src/main/java/io/netty/handler/codec/marshalling/CompatibleMarshallingDecoder.java

@@ -30,7 +30,7 @@ import java.io.ObjectStreamConstants;
  *
  * If you can you should use {@link MarshallingDecoder}.
  */
-public class CompatibleMarshallingDecoder extends ReplayingDecoder<Object, Void> {
+public class CompatibleMarshallingDecoder extends ReplayingDecoder<Void> {
     protected final UnmarshallerProvider provider;
     protected final int maxObjectSize;
     private boolean discardingTooLongFrame;

codec/src/main/java/io/netty/handler/codec/protobuf/ProtobufDecoder.java

@@ -61,7 +61,7 @@ import com.google.protobuf.MessageLite;
  * @apiviz.landmark
  */
 @Sharable
-public class ProtobufDecoder extends MessageToMessageDecoder<ByteBuf, MessageLite> {
+public class ProtobufDecoder extends MessageToMessageDecoder<ByteBuf> {
 
     private final MessageLite prototype;
     private final ExtensionRegistry extensionRegistry;
@@ -84,7 +84,7 @@ public class ProtobufDecoder extends MessageToMessageDecoder<ByteBuf, MessageLit
     }
 
     @Override
-    protected MessageLite decode(ChannelHandlerContext ctx, ByteBuf msg) throws Exception {
+    protected Object decode(ChannelHandlerContext ctx, ByteBuf msg) throws Exception {
         if (msg.hasArray()) {
             final int offset = msg.readerIndex();
             if (extensionRegistry == null) {

codec/src/main/java/io/netty/handler/codec/protobuf/ProtobufEncoder.java

@@ -56,14 +56,14 @@ import com.google.protobuf.MessageLite;
  * @apiviz.landmark
  */
 @Sharable
-public class ProtobufEncoder extends MessageToMessageEncoder<Object, ByteBuf> {
+public class ProtobufEncoder extends MessageToMessageEncoder<Object> {
 
     public ProtobufEncoder() {
         super(MessageLite.class, MessageLite.Builder.class);
     }
 
     @Override
-    protected ByteBuf encode(ChannelHandlerContext ctx, Object msg) throws Exception {
+    protected Object encode(ChannelHandlerContext ctx, Object msg) throws Exception {
         if (msg instanceof MessageLite) {
             return wrappedBuffer(((MessageLite) msg).toByteArray());
         }

codec/src/main/java/io/netty/handler/codec/protobuf/ProtobufVarint32FrameDecoder.java

@@ -37,7 +37,7 @@ import com.google.protobuf.CodedInputStream;
  *
  * @see CodedInputStream
  */
-public class ProtobufVarint32FrameDecoder extends ByteToMessageDecoder<Object> {
+public class ProtobufVarint32FrameDecoder extends ByteToMessageDecoder {
 
     // TODO maxFrameLength + safe skip + fail-fast option
     //      (just like LengthFieldBasedFrameDecoder)

codec/src/main/java/io/netty/handler/codec/string/StringDecoder.java

@@ -52,7 +52,7 @@ import java.nio.charset.Charset;
  * @apiviz.landmark
  */
 @Sharable
-public class StringDecoder extends MessageToMessageDecoder<ByteBuf, String> {
+public class StringDecoder extends MessageToMessageDecoder<ByteBuf> {
 
     // TODO Use CharsetDecoder instead.
     private final Charset charset;
@@ -77,7 +77,7 @@ public class StringDecoder extends MessageToMessageDecoder<ByteBuf, String> {
     }
 
     @Override
-    protected String decode(ChannelHandlerContext ctx, ByteBuf msg) throws Exception {
+    protected Object decode(ChannelHandlerContext ctx, ByteBuf msg) throws Exception {
         return msg.toString(charset);
     }
 }

codec/src/main/java/io/netty/handler/codec/string/StringEncoder.java

@@ -48,7 +48,7 @@ import java.nio.charset.Charset;
  * @apiviz.landmark
  */
 @Sharable
-public class StringEncoder extends MessageToMessageEncoder<CharSequence, ByteBuf> {
+public class StringEncoder extends MessageToMessageEncoder<CharSequence> {
 
     // TODO Use CharsetEncoder instead.
     private final Charset charset;
@@ -73,7 +73,7 @@ public class StringEncoder extends MessageToMessageEncoder<CharSequence, ByteBuf
     }
 
     @Override
-    protected ByteBuf encode(ChannelHandlerContext ctx, CharSequence msg) throws Exception {
+    protected Object encode(ChannelHandlerContext ctx, CharSequence msg) throws Exception {
         return Unpooled.copiedBuffer(msg, charset);
     }
 }

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

@@ -47,7 +47,7 @@ public class ReplayingDecoderTest {
         assertNull(ch.readInbound());
     }
 
-    private static final class LineDecoder extends ReplayingDecoder<ByteBuf, Void> {
+    private static final class LineDecoder extends ReplayingDecoder<Void> {
 
         LineDecoder() {
         }

example/src/main/java/io/netty/example/factorial/BigIntegerDecoder.java

@@ -28,7 +28,7 @@ import java.math.BigInteger;
  * {@link BigInteger} instance.  For example, { 'F', 0, 0, 0, 1, 42 } will be
  * decoded into new BigInteger("42").
  */
-public class BigIntegerDecoder extends ByteToMessageDecoder<BigInteger> {
+public class BigIntegerDecoder extends ByteToMessageDecoder {
 
     @Override
     public BigInteger decode(ChannelHandlerContext ctx, ByteBuf in) {

transport-sctp/src/main/java/io/netty/handler/codec/sctp/SctpMessageToMessageDecoder.java

@@ -20,7 +20,7 @@ import io.netty.channel.socket.sctp.SctpMessage;
 import io.netty.handler.codec.CodecException;
 import io.netty.handler.codec.MessageToMessageDecoder;
 
-public abstract class SctpMessageToMessageDecoder<O> extends MessageToMessageDecoder<SctpMessage, O> {
+public abstract class SctpMessageToMessageDecoder extends MessageToMessageDecoder<SctpMessage> {
 
     @Override
     public boolean isDecodable(Object msg) throws Exception {