Automatic messageType detection for ChannelInboundMessageHandlerAdapter

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

@@ -58,7 +58,6 @@ public class WebSocketServerProtocolHandler extends ChannelInboundMessageHandler
     }
 
     public WebSocketServerProtocolHandler(String websocketPath, String subprotocols, boolean allowExtensions) {
-        super(WebSocketFrame.class);
         this.websocketPath = websocketPath;
         this.subprotocols = subprotocols;
         this.allowExtensions = allowExtensions;

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

@@ -44,7 +44,6 @@ public class WebSocketServerProtocolHandshakeHandler
 
     public WebSocketServerProtocolHandshakeHandler(String websocketPath, String subprotocols,
             boolean allowExtensions) {
-        super(FullHttpRequest.class);
         this.websocketPath = websocketPath;
         this.subprotocols = subprotocols;
         this.allowExtensions = allowExtensions;

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

@@ -37,12 +37,7 @@ public final class SocksServerConnectHandler extends ChannelInboundMessageHandle
         return name;
     }
 
-    private final Bootstrap b;
-
-    public SocksServerConnectHandler() {
-        super(SocksCmdRequest.class);
-        b = new Bootstrap();
-    }
+    private final Bootstrap b = new Bootstrap();
 
     @Override
     public void messageReceived(final ChannelHandlerContext ctx, final SocksCmdRequest request) throws Exception {

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

@@ -34,10 +34,6 @@ public final class SocksServerHandler extends ChannelInboundMessageHandlerAdapte
         return name;
     }
 
-    public SocksServerHandler() {
-        super(SocksRequest.class);
-    }
-
     @Override
     public void messageReceived(ChannelHandlerContext ctx, SocksRequest socksRequest) throws Exception {
         switch (socksRequest.requestType()) {

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

@@ -35,7 +35,6 @@ public class SctpInboundByteStreamHandler extends ChannelInboundMessageHandlerAd
      * @param protocolIdentifier supported application protocol.
      */
     public SctpInboundByteStreamHandler(int protocolIdentifier, int streamIdentifier) {
-        super(SctpMessage.class);
         this.protocolIdentifier = protocolIdentifier;
         this.streamIdentifier = streamIdentifier;
     }

transport-udt/src/test/java/io/netty/test/udt/util/EchoMessageHandler.java

@@ -46,9 +46,6 @@ public class EchoMessageHandler extends
     }
 
     public EchoMessageHandler(final Meter meter, final int messageSize) {
-
-        super(UdtMessage.class);
-
         this.meter = meter;
 
         final ByteBuf byteBuf = Unpooled.buffer(messageSize);

transport/src/main/java/io/netty/channel/ChannelInboundMessageHandlerAdapter.java

@@ -18,6 +18,10 @@ package io.netty.channel;
 import io.netty.buffer.MessageBuf;
 import io.netty.buffer.Unpooled;
 
+import java.lang.reflect.Method;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
 /**
  * {@link ChannelHandler} which handles inbound messages of a specific type.
  *
@@ -43,14 +47,43 @@ import io.netty.buffer.Unpooled;
 public abstract class ChannelInboundMessageHandlerAdapter<I>
         extends ChannelStateHandlerAdapter implements ChannelInboundMessageHandler<I> {
 
-    private final Class<?>[] acceptedMsgTypes;
+    private static final ConcurrentMap<Class<?>, Class<?>> messageTypeMap =
+            new ConcurrentHashMap<Class<?>, Class<?>>();
 
-    /**
-     * The types which will be accepted by the message handler. If a received message is an other type it will be just
-     * forwarded  to the next {@link ChannelInboundMessageHandler} in the {@link ChannelPipeline}.
-     */
-    protected ChannelInboundMessageHandlerAdapter(Class<?>... acceptedMsgTypes) {
-        this.acceptedMsgTypes = ChannelHandlerUtil.acceptedMessageTypes(acceptedMsgTypes);
+    private final Class<?> acceptedMsgType = findMessageType();
+
+    private Class<?> findMessageType() {
+        Class<?> thisClass = getClass();
+        Class<?> messageType = messageTypeMap.get(thisClass);
+        if (messageType == null) {
+            for (Method m: getClass().getDeclaredMethods()) {
+                if (!"messageReceived".equals(m.getName())) {
+                    continue;
+                }
+                if (m.isSynthetic() || m.isBridge()) {
+                    continue;
+                }
+                Class<?>[] p = m.getParameterTypes();
+                if (p.length != 2) {
+                    continue;
+                }
+                if (p[0] != ChannelHandlerContext.class) {
+                    continue;
+                }
+
+                messageType = p[1];
+                break;
+            }
+
+            if (messageType == null) {
+                throw new IllegalStateException(
+                        "cannot determine the inbound message type of " + thisClass.getSimpleName());
+            }
+
+            messageTypeMap.put(thisClass, messageType);
+        }
+
+        return messageType;
     }
 
     @Override
@@ -121,7 +154,7 @@ public abstract class ChannelInboundMessageHandlerAdapter<I>
      * @param msg the message
      */
     public boolean isSupported(Object msg) throws Exception {
-        return ChannelHandlerUtil.acceptMessage(acceptedMsgTypes, msg);
+        return acceptedMsgType.isInstance(msg);
     }
 
     /**

transport/src/test/java/io/netty/channel/DefaultChannelPipelineTest.java

@@ -155,10 +155,6 @@ public class DefaultChannelPipelineTest {
     private static final class StringInboundHandler extends ChannelInboundMessageHandlerAdapter<String> {
         boolean called;
 
-        public StringInboundHandler() {
-            super(String.class);
-        }
-
         @Override
         public boolean isSupported(Object msg) throws Exception {
             called = true;