Fix #153: Add ChannelFuture.rethrowIfFailed()

example/src/main/java/io/netty/example/http/websocketx/client/WebSocketClient.java

@@ -58,6 +58,9 @@ public class WebSocketClient {
                                 Executors.newCachedThreadPool(),
                                 Executors.newCachedThreadPool()));
 
+        Channel ch = null;
+        
+        try {
             String protocol = uri.getScheme();
             if (!protocol.equals("ws")) {
                 throw new IllegalArgumentException("Unsupported protocol: " + protocol);
@@ -93,11 +96,10 @@ public class WebSocketClient {
             ChannelFuture future =
                     bootstrap.connect(
                             new InetSocketAddress(uri.getHost(), uri.getPort()));
-        future.awaitUninterruptibly();
+            future.awaitUninterruptibly().rethrowIfFailed();
     
-        Channel ch = future.getChannel();
-
-        handshaker.handshake(ch).awaitUninterruptibly();
+            ch = future.getChannel();
+            handshaker.handshake(ch).awaitUninterruptibly().rethrowIfFailed();
             
             // Send 10 messages and wait for responses
             System.out.println("WebSocket Client sending message");
@@ -116,9 +118,13 @@ public class WebSocketClient {
             // WebSocketClientHandler will close the connection when the server
             // responds to the CloseWebSocketFrame.
             ch.getCloseFuture().awaitUninterruptibly();
-
+        } finally {
+            if (ch != null) {
+                ch.close();
+            }
             bootstrap.releaseExternalResources();
         }
+    }
 
     public static void main(String[] args) throws Exception {
         URI uri;

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

@@ -258,6 +258,12 @@ public interface ChannelFuture {
      */
     void removeListener(ChannelFutureListener listener);
 
+    /**
+     * Rethrows the exception that caused this future fail if this future is
+     * complete and failed.
+     */
+    ChannelFuture rethrowIfFailed() throws Exception;
+
     /**
      * Waits for this future to be completed.
      *

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

@@ -175,6 +175,28 @@ public class DefaultChannelFuture implements ChannelFuture {
         }
     }
 
+    @Override
+    public ChannelFuture rethrowIfFailed() throws Exception {
+        if (!isDone()) {
+            return this;
+        }
+        
+        Throwable cause = getCause();
+        if (cause == null) {
+            return this;
+        }
+
+        if (cause instanceof Exception) {
+            throw (Exception) cause;
+        }
+
+        if (cause instanceof Error) {
+            throw (Error) cause;
+        }
+
+        throw new RuntimeException(cause);
+    }
+
     @Override
     public ChannelFuture await() throws InterruptedException {
         if (Thread.interrupted()) {

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

@@ -47,4 +47,17 @@ public class FailedChannelFuture extends CompleteChannelFuture {
     public boolean isSuccess() {
         return false;
     }
+
+    @Override
+    public ChannelFuture rethrowIfFailed() throws Exception {
+        if (cause instanceof Exception) {
+            throw (Exception) cause;
+        }
+        
+        if (cause instanceof Error) {
+            throw (Error) cause;
+        }
+        
+        throw new RuntimeException(cause);
+    }
 }

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

@@ -40,4 +40,9 @@ public class SucceededChannelFuture extends CompleteChannelFuture {
     public boolean isSuccess() {
         return true;
     }
+
+    @Override
+    public ChannelFuture rethrowIfFailed() throws Exception {
+        return this;
+    }
 }

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

@@ -99,6 +99,11 @@ public class CompleteChannelFutureTest {
         public boolean isSuccess() {
             throw new Error();
         }
+        
+        @Override
+        public ChannelFuture rethrowIfFailed() throws Exception {
+            throw new Error();
+        }
     }
 
     private static class ExpectedError extends Error {