Retry constructing a thread/ terminate thread

[coyote1982]

Hi,
not sure this is a beginner's question...

I have a class (which is called EventThread) that extends the Thread class and I want its constructor to try opening a Socket to some server. I would like to make it try and reconnect everytime it fails opening that Socket (when the server is unavailable, for example). I have surrounded the statement:
new EventThread(serverIP, serverListeningPort).start();
with a try block and a while block, like so:
do {

try {

new EventThread(serverIP, serverListeningPort).start();
retry = false;

} catch (Exception e) {

System.out.println("Trying to reconnect...");
retry = true;

}

}
while (retry);

When the EventThread constructor fails to open a Socket it throws an IOException which is caught in a catch block. I thought that if I call the interrupt method from within that catch block, it would stop that thread and return to the class that invoked it (where the do-while block is), but instead EventThread continues to its run method and obviously throws an exception since it didn't establish a connection with the server.
what's the right way to accomplish this?

Thanks

[Tolls]

What's the constructor code for your EventThread?

[quad64bit]

Put all the code inside the run() method instead. if everything is in a loop, then it will try forever until you terminate it from outside the thread. Make sure after instantiation that you call the start() method on the thread to get it going :D

[coyote1982]

What's the constructor code for your EventThread?

here it is:
public class EventThread extends Thread {

private Socket eventSocket;

public EventThread(String serverIP, int serverListeningPort) {

super("EventThread");
try {

this.eventSocket = new Socket(serverIP, serverListeningPort);

} catch (UnknownHostException e) {

System.err.println("Unable to locate server.");
System.exit(1);

} catch (IOException e) {

System.err.println("error occured while trying to connect to server on: " +
serverIP + ":" + serverListeningPort);
System.exit(1);

}

}

}

[coyote1982]

I've found a way to do what I wanted. here it is, if anyone's interested:

do {

EventThread eventThread = new EventThread(serverIP, serverListeningPort);
if (eventThread.getEventSocket() == null) {

System.out.println("Trying to reconnect...");
continue;

}
eventThread.start();

} while (true);

[Tolls]

Your original idea is sort of OK, though you seem a bit confused as to when a thread is launched (not until start() is called).

I don't quite understand, if an exception was thrown by new Socket(), why your app didn't simply shutdown. Take the following test code:

public class Test2 {
	private static class EventThread extends Thread
	{
		public EventThread() {
			super("EventThread");
			try {
				throw new Exception("Test exception");
			} catch (Exception e) {
				e.printStackTrace();
				System.exit(1);
			}
		}
		
		@Override
		public void run()
		{
			System.out.println("I'm running");
		}

	}
	public static void main(String args[]) {
		EventThread et = new EventThread();
		et.start();
		System.out.println("blah");
	}
}

This does what yours does, assuming new Socket() throws an exception. I've simply taken out that bit and thrown an exception straight off the bat.

This outputs:

java.lang.Exception: Test exception
at dave.Test2$EventThread.<init>(Test2.java:51)
at dave.Test2.main(Test2.java:66)

as I'd expect, since the exit(1) has killed the system before the start() is called.

So I can only assume something else was going on in your code.

By the way, rather than calling System.exit() I would have thrown an exception which the outer code would catch, rather than a check on null.

[coyote1982]

@Tolls

Thanks for the reply...I did remove the System.exit() and it works perfectly