[news.eclipse.platform.swt] Re: Listening on 2 ports same time from SWT

[Stefan Langer <eclipse@xxxxxxxxxxxxxxxxxxxx>]

sumit panchasara wrote:
> Hi!
> ya it is blocked. But by creating threads also it will make number of 
> threads for the same port. I want to connect to different port address.
> "Stefan Langer" <eclipse@xxxxxxxxxxxxxxxxxxxx> wrote in message 
> news:d86ol8$r9f$1@xxxxxxxxxxxxxxxxxxx
>
> > sumit panchasara wrote:
> >
> > > Hi,
> > > I made one SWT app. using Eclipse. I am creating two buttons for server1,
> > > server2 in a single application. When I press server1 it should start
> > > listening on port 5555 and on pressing server2, should start listening on
> > > 6666.
> > > Clients issues related commands and servers should accept both
> > > connections(on related ports). e.g. client1 issues command for port 5555 
> > > and
> > > client2 issues command for port 6666.
> > >
> > > All clients are different machines.
> > > Servers are on same machine. i.e. it is only one but listening on two
> > > different ports.
> > >
> > > Communication Protocol I have used is TCP/IP.
> > >
> > > Now every thing is working fine. But for only one of these port. server
> > > doesn't allow me to listen on second port. i.e. after pressing server1 I 
> > > can
> > > not able to press server2. Thus Client listening on port 6666 for 
> > > example,
> > > will not able to build connection with server.
> > >
> > > What to do in this case?
> > >
> > > Sumit.
> >
> > How are you establishing the connection? Are you creating new Threads to 
> > connect to server or are you doing it in the eventdispatch thread? If so 
> > then you are blocking the whole ui.
> >
> > Regards
> > Stefan 
Spawn a Thread for every Port you are opening and keep track of the 
thread. If the thread is allready started simply ignore the request of 
the button. If it has not been started create a Thread and start it to 
listen on the requested port.
If you are using 1.4 or higher try using nonblocking IO.
In Order to keep the user from pressing the button more than once you 
might try to disable it when the thread for listening on the port has 
been spawned.

Something along the lines

Button btnPort55 = new Button(parent, SWT.PUSH);
btnPort55.addActionListener(new SelectionListener() {
  public void widgetDefaultSelected(SelectionEvent e)
  {
	spawnThread(66);
  }
		
  public void widgetSelected(SelectionEvent e)
  {
	spawnThread(55);
  }
});

Button btnPort66 = new Button(parent, SWT.PUSH);
btnPort66.addActionListener(new SelectionListener() {
  public void widgetDefaultSelected(SelectionEvent e)
  {
	spawnThread(66);
  }
		
  public void widgetSelected(SelectionEvent e)
  {
	spawnThread(55);
  }
});

spawnThread(int port)
{
   Thread thread = this.threads_.get(new Integer(port));
   if(!thread.isAlive())
	thread.start();
}

threads_ is a HashMap that holds all the threads that need to listen to 
a port keyed by the portnumber. To prevent the user from pressing the 
buttons while a thread is running simply disable them with
btnPort55.setEnabled(false);

That should give you a clue.

Regards
Stefan

P.S.: Don't forget that you can only update the ui in the eventdispatch 
thread use execAsync or execSync to execute code for the ui in your 
spawned Threads.