Thread: Problem controlling a ctrl + c signal by console

hi! first of all tell me if you doesn't understand something of my post.

I'm programming a Java chat with a server and several clients (all of them in separate consoles). Everething is alright when I run the server, then a client, the other client...

My problem is that I have to control the "ctrl + c" signal (in the client). In the source code I've implemented this function:

Runtime.getRuntime().addShutdownHook(new Thread(new Runnable(){
public void run (){
try {
System.out.println("Ctrl + c pressed");
Client.disconnect(s, c);
finalize();
} catch (Throwable ex) {
Logger.getLogger(Client.class.getName()).log(Level .SEVERE, null, ex);
}
}
}));

My program lets me pressed ctrl + c but it doesn't enter in this funcion because, this "Ctrl + c pressed" is never printed. That is why my server doesn't remove the client of the list...

Does anyone know why that happend??

Best.

Ups sorry,

ServerInterface s;
Client c;

They are only my instances of the server and the client. With that sentence I pretend to remove the client of the list which is managed by the server.

What do you mean? :S

I agree with copeg - a cut down example that illustrates the problem will clear things up. (and answer questions like whether the hook ever gets added.)

As an aside I wonder about whether a shutdown hook on the client will be enough. The slings and arrows of the web are such that the client/server link might get severed without the clean disconnect() method ever getting called. So the server might need to take some action to make sure its list of clients is valid.

I found the problem, I used a "while(true)" loop for reading (with Scanner class) the messages that the client could send to another, and the RunTime function which cautch the signal "SIGINT". When I pressed ctrl + C (as I was a client) RunTime caught the signal but didn't give me the control line again. Now I substitute with a "do while" loop and it works. But I don't understand why. Someone can explain me why it works with the do while loop and not the other way around?