Remove methods Utility.use() and Utility.emptyStatement() and all uses.

Author: Steve Powell

src/com/rabbitmq/client/impl/AMQConnection.java

@@ -578,9 +578,7 @@ public boolean processControlCommand(Command c) throws IOException
                 // Already shutting down, so just send back a CloseOk.
                 try {
                     _channel0.quiescingTransmit(new AMQP.Connection.CloseOk.Builder().build());
-                } catch (IOException ioe) {
-                    Utility.emptyStatement();
-                }
+                } catch (IOException ioe) { } // ignore
                 return true;
             } else if (method instanceof AMQP.Connection.CloseOk) {
                 // It's our final "RPC". Time to shut down.
@@ -599,9 +597,7 @@ public void handleConnectionClose(Command closeCommand) {
         ShutdownSignalException sse = shutdown(closeCommand, false, null, false);
         try {
             _channel0.quiescingTransmit(new AMQP.Connection.CloseOk.Builder().build());
-        } catch (IOException ioe) {
-            Utility.emptyStatement();
-        }
+        } catch (IOException _) { } // ignore
         _brokerInitiatedShutdown = true;
         Thread scw = new SocketCloseWait(sse);
         scw.setName("AMQP Connection Closing Monitor " +
@@ -708,9 +704,7 @@ public void abort(int closeCode, String closeMessage, int timeout)
     {
         try {
             close(closeCode, closeMessage, true, null, timeout, true);
-        } catch (IOException e) {
-            Utility.emptyStatement();
-        }
+        } catch (IOException _) { } // ignore
     }
 
     /**

src/com/rabbitmq/client/impl/ChannelN.java

@@ -121,10 +121,8 @@ public ChannelN(AMQConnection connection, int channelNumber,
      * @throws IOException if any problem is encountered
      */
     public void open() throws IOException {
-        // wait for the Channel.OpenOk response, then ignore it
-        Channel.OpenOk openOk =
-            (Channel.OpenOk) exnWrappingRpc(new Channel.Open(UNSPECIFIED_OUT_OF_BAND)).getMethod();
-        Utility.use(openOk);
+        // wait for the Channel.OpenOk response, and ignore it
+        exnWrappingRpc(new Channel.Open(UNSPECIFIED_OUT_OF_BAND));
     }
 
     public void addReturnListener(ReturnListener listener) {
@@ -909,8 +907,7 @@ public void basicCancel(final String consumerTag)
     {
         BlockingRpcContinuation<Consumer> k = new BlockingRpcContinuation<Consumer>() {
             public Consumer transformReply(AMQCommand replyCommand) {
-                Basic.CancelOk dummy = (Basic.CancelOk) replyCommand.getMethod();
-                Utility.use(dummy);
+                replyCommand.getMethod(); // discard result
                 Consumer callback = _consumers.remove(consumerTag);
                 // We need to call back inside the connection thread
                 // in order avoid races with 'deliver' commands
@@ -922,8 +919,7 @@ public Consumer transformReply(AMQCommand replyCommand) {
         rpc(new Basic.Cancel(consumerTag, false), k);
 
         try {
-            Consumer callback = k.getReply();
-            Utility.use(callback);
+            k.getReply(); // discard result
         } catch(ShutdownSignalException ex) {
             throw wrap(ex);
         }

src/com/rabbitmq/utility/Utility.java

@@ -33,9 +33,9 @@ public ThrowableCreatedElsewhere(Throwable throwable) {
           this.setStackTrace(throwable.getStackTrace());
         }
 
-        @Override public Throwable fillInStackTrace(){ 
-            return this; 
-        } 
+        @Override public Throwable fillInStackTrace(){
+            return this;
+        }
     }
 
     public static <T extends Throwable & SensibleClone<T>> T fixStackTrace(T throwable) {
@@ -44,19 +44,19 @@ public static <T extends Throwable & SensibleClone<T>> T fixStackTrace(T throwab
       if(throwable.getCause() == null) {
         // We'd like to preserve the original stack trace in the cause.
         // Unfortunately Java doesn't let you set the cause once it's been
-        // set once. This means we have to choose between either 
+        // set once. This means we have to choose between either
         //  - not preserving the type
         //  - sometimes losing the original stack trace
         //  - performing nasty reflective voodoo which may or may not work
         // We only lose the original stack trace when there's a root cause
-        // which will hopefully be enlightening enough on its own that it 
-        // doesn't matter too much. 
+        // which will hopefully be enlightening enough on its own that it
+        // doesn't matter too much.
         try {
           throwable.initCause(new ThrowableCreatedElsewhere(throwable));
         } catch(IllegalStateException e) {
-          // This exception was explicitly initialised with a null cause. 
-          // Alas this means we can't set the cause even though it has none. 
-          // Thanks. 
+          // This exception was explicitly initialised with a null cause.
+          // Alas this means we can't set the cause even though it has none.
+          // Thanks.
         }
       }
 
@@ -70,7 +70,7 @@ public static <T extends Throwable & SensibleClone<T>> T fixStackTrace(T throwab
       return throwable;
     }
 
-  
+
     public static String makeStackTrace(Throwable throwable) {
         ByteArrayOutputStream baOutStream = new ByteArrayOutputStream();
         PrintStream printStream = new PrintStream(baOutStream, false);
@@ -80,22 +80,4 @@ public static String makeStackTrace(Throwable throwable) {
         printStream.close(); // closes baOutStream
         return text;
     }
-
-    /**
-     * Used to indicate that we are not, in fact, using a variable, also to silence compiler warnings.
-     *
-     * @param value the object we're pretending to use
-     */
-    public static void use(Object value) {
-        if (value != null) {
-            return;
-        }
-    }
-
-    /**
-     * Similarly, for situations where an empty statement is required
-     */
-    public static void emptyStatement() {
-        use(null);
-    }
 }

test/src/com/rabbitmq/examples/TestMain.java

@@ -39,7 +39,6 @@
 import com.rabbitmq.client.impl.FrameHandler;
 import com.rabbitmq.client.impl.SocketFrameHandler;
 import com.rabbitmq.utility.BlockingCell;
-import com.rabbitmq.utility.Utility;
 
 public class TestMain {
     public static void main(String[] args) throws IOException, URISyntaxException {
@@ -199,9 +198,7 @@ public static void runProducerConsumerTest(String uri, int commitEvery)
     public static void sleep(int ms) {
         try {
             Thread.sleep(ms);
-        } catch (InterruptedException ie) {
-            Utility.emptyStatement();
-        }
+        } catch (InterruptedException _) { } // ignore
     }
 
     private Connection _connection;
@@ -232,7 +229,7 @@ public void run() throws IOException {
         final int batchSize = 5;
 
         _ch1 = createChannel();
-        
+
         String queueName =_ch1.queueDeclare().getQueue();
 
         sendLotsOfTrivialMessages(batchSize, queueName);
@@ -488,7 +485,7 @@ public void tryBasicReturn() throws IOException {
         unsetChannelReturnListener();
 
         log("Completed basic.return testing.");
-        
+
     }
 
     private void unsetChannelReturnListener() {