Add channel number to ChannelContinuationTimeoutException

Fixes #219

Author: acogoluegnes

src/main/java/com/rabbitmq/client/ChannelContinuationTimeoutException.java

@@ -11,25 +11,53 @@ public class ChannelContinuationTimeoutException extends IOException {
 
     /**
      * The channel that performed the call.
+     * Typed as <code>Object</code> as the underlying
+     * object that performs the call might
+     * not be an implementation of {@link Channel}.
      */
     private final Object channel;
 
+    /**
+     * The number of the channel that performed the call.
+     */
+    private final int channelNumber;
+
     /**
      * The request method that timed out.
      */
     private final Method method;
 
-    public ChannelContinuationTimeoutException(TimeoutException cause, Object channel, Method method) {
-        super(cause);
+    public ChannelContinuationTimeoutException(TimeoutException cause, Object channel, int channelNumber, Method method) {
+        super(
+            "Continuation call for method " + method + " on channel " + channel + " (#" + channelNumber + ") timed out",
+            cause
+        );
         this.channel = channel;
+        this.channelNumber = channelNumber;
         this.method = method;
     }
 
+    /**
+     *
+     * @return request method that timed out
+     */
     public Method getMethod() {
         return method;
     }
 
+    /**
+     * channel that performed the call
+     * @return
+     */
     public Object getChannel() {
         return channel;
     }
+
+    /**
+     *
+     * @return number of the channel that performed the call
+     */
+    public int getChannelNumber() {
+        return channelNumber;
+    }
 }

src/main/java/com/rabbitmq/client/impl/AMQChannel.java

@@ -250,7 +250,7 @@ private AMQCommand privateRpc(Method m)
                 } catch(Exception ex) {
                     LOGGER.warn("Error while cleaning timed out channel RPC: {}", ex.getMessage());
                 }
-                throw new ChannelContinuationTimeoutException(e, this, m);
+                throw new ChannelContinuationTimeoutException(e, this, this._channelNumber, m);
             }
         }
     }

src/test/java/com/rabbitmq/client/test/AMQChannelTest.java

@@ -69,6 +69,7 @@ public class AMQChannelTest {
         } catch(ChannelContinuationTimeoutException e) {
             // OK
             assertThat((DummyAmqChannel) e.getChannel(), is(channel));
+            assertThat(e.getChannelNumber(), is(channel.getChannelNumber()));
             assertThat(e.getMethod(), is(method));
             assertNull("outstanding RPC should have been cleaned", channel.nextOutstandingRpc());
         }

src/test/java/com/rabbitmq/client/test/ChannelRpcTimeoutIntegrationTest.java

@@ -76,6 +76,7 @@ public void tearDown() throws Exception {
             } catch(ChannelContinuationTimeoutException e) {
                 // OK
                 assertThat((Channel) e.getChannel(), is(channel));
+                assertThat(e.getChannelNumber(), is(channel.getChannelNumber()));
                 assertThat(e.getMethod(), instanceOf(AMQP.Queue.Declare.class));
             }
         } finally {