Serialization and JComponents with ActionListeners

Sorry, I have to ignore your request and ask why you want to do it. A lot of people have some funny ideas about serialization, that leads them to try things that neither make sense nor actually solve their problem. Listeners should be stateless, so serializing them is pointless. I'm wondering what state of the object it is you're actually interested in. If you have the class bytes of your JComponent at the other end (and you have to, if you want to serialize it) you can already re-construct the JComponent (and listeners) without serializing it. If there's additional state you want to send across the wire (size of JComponent, other application data) you could put that all in a separate object and serialize that

But I doubt very much that what you're attempting is actually what you need to do. Can you give more info about what you're trying to achieve?

georgemca at 2007-7-28 17:57:04 >

Ah, if I get you right, you want to basically remotely configure a JFrame with listeners. Ok, you've got a couple of options here. I

f you have a known set of Listeners, that is fixed, you have those classes at both ends, and part of the configuration for the component will include a list of strings which are the classnames of those listeners. You can easily serialize that and send it across the wire. At the other end, your component used a bit of reflection to instantiate the appropriate listeners and add them to itself.

If you want to add new types of listener without having to have them available on the other side of the wire up-front, you could have a custom classloader which pulls its class bytes over the wire, loads the class(es) then instantiates and adds them

The reason ActionListeners aren't serializable is that it doesn't really make sense to serialize them. They don't (typically) maintain state, so there's nothing other than the class bytes to be serialized, and class bytes are already serialized since they exist as, well, a stream of bytes

If that's not clear, do ask me to explain. I'm just in a bit of a rush at the moment!

georgemca at 2007-7-28 17:57:04 >

Other people can of course mail me, too. Im very interested in the reasons why Listeners are not serializable.

Sandmann6a at 2007-7-28 17:57:04 >

Ok, lets look at a concrete example.

The Service Interface is something like that:

public interface ButtonTest extends Remote{

public JComponent getJComponent() throws RemoteException;

}

And then I have a class

public class Test implements ButtonTest, ActionListener{

public JComponent getJcomponent(){

JButton button = new JButton();

button.setText("TEST");

button.addActionListener(this);

return button;

}

public void actiuonperformed(Event e){

System.out.println("THIS IS A TEST");

}

}

Now I want this button on the other side with the same behaviour. Is there a direct way which makes this possible ? Im just geeting crazy because of that problem!

Message was edited by:

Sandmann6

Sandmann6a at 2007-7-28 17:57:04 >

Hi,

You wont believe it, but it works.

If I put only the Listener and a JComponent in a seperate class (not in a UnicastRemoteObject) and send it over the net via RMI, I have the JComponent with the listener at the Client side.

I thought I tried this so many times and it didnt work, but now it does.....

So thank you so much. You will earn of course all the duke points for this topic!!!

Sandmann6a at 2007-7-28 17:57:04 >