Made the echo example easier to understand by splitting EchoHandler into EchoClientHandler and EchoServerHandler

src/main/java/org/jboss/netty/example/echo/EchoClient.java

@@ -60,7 +60,7 @@ public class EchoClient {
                         Executors.newCachedThreadPool()));
 
         // Set up the default event pipeline.
-        EchoHandler handler = new EchoHandler(firstMessageSize);
+        EchoClientHandler handler = new EchoClientHandler(firstMessageSize);
         bootstrap.getPipeline().addLast("handler", handler);
 
         // Start the connection attempt.

src/main/java/org/jboss/netty/example/echo/EchoClientHandler.java

@@ -29,8 +29,9 @@ import org.jboss.netty.channel.MessageEvent;
 import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
 
 /**
- * Handles both client-side and server-side handler depending on which
- * constructor was called.
+ * 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.
  *
  * @author The Netty Project (netty-dev@lists.jboss.org)
  * @author Trustin Lee (tlee@redhat.com)
@@ -38,25 +39,18 @@ import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
  * @version $Rev$, $Date$
  */
 @ChannelPipelineCoverage("all")
-public class EchoHandler extends SimpleChannelUpstreamHandler {
+public class EchoClientHandler extends SimpleChannelUpstreamHandler {
 
     private static final Logger logger = Logger.getLogger(
-            EchoHandler.class.getName());
+            EchoClientHandler.class.getName());
 
     private final ChannelBuffer firstMessage;
     private final AtomicLong transferredBytes = new AtomicLong();
 
-    /**
-     * Creates a server-side handler.
-     */
-    public EchoHandler() {
-        firstMessage = ChannelBuffers.EMPTY_BUFFER;
-    }
-
     /**
      * Creates a client-side handler.
      */
-    public EchoHandler(int firstMessageSize) {
+    public EchoClientHandler(int firstMessageSize) {
         if (firstMessageSize <= 0) {
             throw new IllegalArgumentException(
                     "firstMessageSize: " + firstMessageSize);

src/main/java/org/jboss/netty/example/echo/EchoServer.java

@@ -40,7 +40,7 @@ public class EchoServer {
                         Executors.newCachedThreadPool()));
 
         // Set up the default event pipeline.
-        EchoHandler handler = new EchoHandler();
+        EchoServerHandler handler = new EchoServerHandler();
         bootstrap.getPipeline().addLast("handler", handler);
 
         // Bind and start to accept incoming connections.

src/main/java/org/jboss/netty/example/echo/EchoServerHandler.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2009 Red Hat, Inc.
+ *
+ * Red Hat licenses this file to you under the Apache License, version 2.0
+ * (the "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at:
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+package org.jboss.netty.example.echo;
+
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import org.jboss.netty.buffer.ChannelBuffer;
+import org.jboss.netty.channel.ChannelHandlerContext;
+import org.jboss.netty.channel.ChannelPipelineCoverage;
+import org.jboss.netty.channel.ExceptionEvent;
+import org.jboss.netty.channel.MessageEvent;
+import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
+
+/**
+ * Handler implementation for the echo server.
+ *
+ * @author The Netty Project (netty-dev@lists.jboss.org)
+ * @author Trustin Lee (tlee@redhat.com)
+ *
+ * @version $Rev: 1685 $, $Date: 2009-08-28 16:15:49 +0900 (Fri, 28 Aug 2009) $
+ */
+@ChannelPipelineCoverage("all")
+public class EchoServerHandler extends SimpleChannelUpstreamHandler {
+
+    private static final Logger logger = Logger.getLogger(
+            EchoServerHandler.class.getName());
+
+    private final AtomicLong transferredBytes = new AtomicLong();
+
+    public long getTransferredBytes() {
+        return transferredBytes.get();
+    }
+
+    @Override
+    public void messageReceived(
+            ChannelHandlerContext ctx, MessageEvent e) {
+        // Send back the received message to the remote peer.
+        transferredBytes.addAndGet(((ChannelBuffer) e.getMessage()).readableBytes());
+        e.getChannel().write(e.getMessage());
+    }
+
+    @Override
+    public void exceptionCaught(
+            ChannelHandlerContext ctx, ExceptionEvent e) {
+        // Close the connection when an exception is raised.
+        logger.log(
+                Level.WARNING,
+                "Unexpected exception from downstream.",
+                e.getCause());
+        e.getChannel().close();
+    }
+}

src/main/java/org/jboss/netty/example/echo/ThroughputMonitor.java

@@ -15,6 +15,8 @@
  */
 package org.jboss.netty.example.echo;
 
+import org.jboss.netty.channel.ChannelHandler;
+
 /**
  * Measures and prints the current throughput every 3 seconds.
  *
@@ -25,15 +27,19 @@ package org.jboss.netty.example.echo;
  */
 public class ThroughputMonitor extends Thread {
 
-    private final EchoHandler handler;
+    private final ChannelHandler handler;
 
-    public ThroughputMonitor(EchoHandler handler) {
+    public ThroughputMonitor(EchoClientHandler handler) {
+        this.handler = handler;
+    }
+
+    public ThroughputMonitor(EchoServerHandler handler) {
         this.handler = handler;
     }
 
     @Override
     public void run() {
-        long oldCounter = handler.getTransferredBytes();
+        long oldCounter = getTransferredBytes();
         long startTime = System.currentTimeMillis();
         for (;;) {
             try {
@@ -43,7 +49,7 @@ public class ThroughputMonitor extends Thread {
             }
 
             long endTime = System.currentTimeMillis();
-            long newCounter = handler.getTransferredBytes();
+            long newCounter = getTransferredBytes();
             System.err.format(
                     "%4.3f MiB/s%n",
                     (newCounter - oldCounter) * 1000.0 / (endTime - startTime) /
@@ -52,4 +58,12 @@ public class ThroughputMonitor extends Thread {
             startTime = endTime;
         }
     }
+
+    private long getTransferredBytes() {
+        if (handler instanceof EchoClientHandler) {
+            return ((EchoClientHandler) handler).getTransferredBytes();
+        } else {
+            return ((EchoServerHandler) handler).getTransferredBytes();
+        }
+    }
 }

src/main/java/org/jboss/netty/example/http/tunnel/LocalEchoServerRegistration.java

@@ -20,7 +20,7 @@ import org.jboss.netty.channel.Channel;
 import org.jboss.netty.channel.ChannelFactory;
 import org.jboss.netty.channel.local.DefaultLocalServerChannelFactory;
 import org.jboss.netty.channel.local.LocalAddress;
-import org.jboss.netty.example.echo.EchoHandler;
+import org.jboss.netty.example.echo.EchoServerHandler;
 
 /**
  * Deploy this in JBossAS 5 or other IoC container by adding the following bean.
@@ -41,7 +41,7 @@ public class LocalEchoServerRegistration {
 
     public void start() {
         ServerBootstrap serverBootstrap = new ServerBootstrap(factory);
-        EchoHandler handler = new EchoHandler();
+        EchoServerHandler handler = new EchoServerHandler();
         serverBootstrap.getPipeline().addLast("handler", handler);
 
         // Note that "myLocalServer" is the endpoint which was specified in web.xml.

src/main/java/org/jboss/netty/example/local/LocalExample.java

@@ -24,7 +24,7 @@ import org.jboss.netty.channel.ChannelFuture;
 import org.jboss.netty.channel.local.DefaultLocalClientChannelFactory;
 import org.jboss.netty.channel.local.DefaultLocalServerChannelFactory;
 import org.jboss.netty.channel.local.LocalAddress;
-import org.jboss.netty.example.echo.EchoHandler;
+import org.jboss.netty.example.echo.EchoServerHandler;
 import org.jboss.netty.handler.codec.string.StringDecoder;
 import org.jboss.netty.handler.codec.string.StringEncoder;
 import org.jboss.netty.handler.logging.LoggingHandler;
@@ -45,7 +45,7 @@ public class LocalExample {
                 new DefaultLocalServerChannelFactory());
 
         // Set up the default server-side event pipeline.
-        EchoHandler handler = new EchoHandler();
+        EchoServerHandler handler = new EchoServerHandler();
         sb.getPipeline().addLast("handler", handler);
 
         // Start up the server.