Question

I implemented an own Marshalling/Unmarshalling Sytem with JMS (exercise). I do Request and get Responses back. I want to fire an own callback in response after i received the correct response. But i think my exception is a serialization problem. But i don’t know how to fix it.

I use that code to call a server

button.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {
            Request request = new Request("printServer:" + printMessage.getText());
            request.setAsyncCallback(new AsyncCallback() {

                /**
                 * 
                 */
                private static final long serialVersionUID = 5204649755139243369L;

                @Override
                public void onSuccess(String content) {
                    System.out.println("async callback: " + content);

                }
            });
            c.callServer(request);

        }
    });

My request looks like this:

public class Request extends Conveyable
{
private static final long serialVersionUID = 4535036450648916878L;

public static int requestIDInc = 0;

private int requestID;

private AsyncCallback callback;

public Request(String content)
{
    super(content);
    synchronized (this) {
        requestID = ++requestIDInc;
    }   
}

public int getRequestID() {
    return requestID;


}

public AsyncCallback getAsyncCallback() {
    // TODO Auto-generated method stub
    return callback;
}

public void setAsyncCallback(AsyncCallback callback)
{
    this.callback = callback;
}

}

My own Callback looks like this:

public abstract class AsyncCallback implements Serializable{
/**
 * 
 */
private static final long serialVersionUID = 4951246599084406476L;

public abstract void onSuccess(String content);

}

And the exception i got is this:

javax.jms.MessageFormatException: machines.client.ClientWindow$1
at org.exolab.jms.message.ObjectMessageImpl.setObject(ObjectMessageImpl.java:194)

It looks a little bit as if the ClientWindow in which a create the Request and fire it off with a buttonClick is included in this callback. But i don’t know why. Or maybe the problem isn’t there.

Answer 1

Your subclass of AsyncCallback is created as an inner class inside ClientWindow. Non-static inner classes contain a reference back to the parent class.