Java.lang.IllegalMonitorStateException problem

Question

Hi all,
I'm using Future objects but I'm getting java.lang.IllegalMonitorStateException.
The stack trace is the following:
java.util.concurrent.ExecutionException: java.lang.IllegalMonitorStateException: current thread not owner
[java]      at java.util.concurrent.FutureTask$Sync.innerGet(FutureTask.java:215)
[java]      at java.util.concurrent.FutureTask.get(FutureTask.java:85)
[java]      at stock.GUI$1.mouseClicked(GUI.java:168)
[java]      at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:212)
[java]      at java.awt.Component.processMouseEvent(Component.java:5491)
[java]      at javax.swing.JComponent.processMouseEvent(JComponent.java:3126)
[java]      at java.awt.Component.processEvent(Component.java:5253)
[java]      at java.awt.Container.processEvent(Container.java:1966)
[java]      at java.awt.Component.dispatchEventImpl(Component.java:3955)
[java]      at java.awt.Container.dispatchEventImpl(Container.java:2024)
[java]      at java.awt.Component.dispatchEvent(Component.java:3803)
[java]      at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4212)
[java]      at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3901)
[java]      at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3822)
[java]      at java.awt.Container.dispatchEventImpl(Container.java:2010)
[java]      at java.awt.Window.dispatchEventImpl(Window.java:1774)
[java]      at java.awt.Component.dispatchEvent(Component.java:3803)
[java]      at java.awt.EventQueue.dispatchEvent(EventQueue.java:463)
[java]      at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:242)
[java]      at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:163)
[java]      at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)
[java]      at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)
[java]      at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)
[java] Caused by: java.lang.IllegalMonitorStateException: current thread not owner
[java]      at java.lang.Object.wait(Native Method)
[java]      at dsm.mrmw.ReadHandler.remoteRead(ReadHandler.java:145)
[java]      at dsm.mrmw.ReadHandler.call(ReadHandler.java:107)
[java]      at dsm.mrmw.ReadHandler.call(ReadHandler.java:28)
[java]      at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:269)
[java]      at java.util.concurrent.FutureTask.run(FutureTask.java:123)
[java]      at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:650)
[java]      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:675)
[java]      at java.lang.Thread.run(Thread.java:595)
where:
- the chunk of code in GUI.java is
try {
   Future<ISharedObject> result = memory.read(address); // the "read" call creates a ReadHandler object to satisfy the request
   try {
     SharedObject value = result.get(3, TimeUnit.SECONDS);   // line 168
     Stock s = (Stock) value.getObject();
   } catch (InterruptedException e1) {
     e1.printStackTrace();
   } catch (ExecutionException e1) {
     e1.printStackTrace();
  } catch (TimeoutException e1) {
     e1.printStackTrace();
} catch (BadAddressException e1) {
     e1.printStackTrace();
}while the chunk of code responsible for the exception in ReadHandler, a Callable object, is:
// the line 107 is the call of this method
private final ISharedObject remoteRead() throws ReadException,
     DuplicateRequestException {
          try {
                *  Creates a new destination and stores it into the
                *  subscriptions hash table.
               Subscription toSubscribe = subscribe();
               // Sends "synchronization" request ONLY if this subscription is
               // not already present.
               if (subscriptions.putIfAbsent(
                         toSubscribe.destination, toSubscribe) == null) {
                    toSubscribe.sendRequestMsg();
               if (memory.queueThread(address.toString(), this) == null) {
                    try {
                         wait(timeoutInMillisecs);   // line 145
                    } catch (InterruptedException e) {
                         Thread.currentThread().interrupt();
                    return memory.get(address);
               // else the request has already been submitted but it's still pending
               throw new DuplicateRequestException();
          } catch (NamingException e) {
               if (logger.isEnabledFor(Level.INFO)) {
                    logger.info("Unable to satisfy the remote read request: " +
                              e.getLocalizedMessage());
               throw new ReadException();
          } catch (JMSException e) {
               if (logger.isEnabledFor(Level.INFO)) {
                    logger.info("Unable to satisfy the remote read request: " +
                              e.getLocalizedMessage());
               throw new ReadException();
          } finally {
               memory.removeWaitingThread(address.getDestination());
     }How can I solve this error?
Best regards,
Michele

Answer 1

I'll reply by by own: the solution seems to be making the remoteRead() method synchronized (or to use a synchronized block)