main thread question?

[frejon26]

are there any problems that arise from letting the main thread finish execution before sibling threads finish. I know the thread.join() method prevents this when you have a reference to the thread object running.

on my computer it does not seem to casue any visible problems.

-thanks

[roots]

Java Doc Thread Class and Thread.setDaemon() and this link might help you.

I played with this code

import java.io.FileNotFoundException;
import java.io.PrintStream;

public class TheTenthMonth implements Runnable{
	public static void main(String[] args) throws Exception {
		Thread thread = new Thread(new TheTenthMonth());
		// thread.setDaemon(true);
		thread.start();
		
		System.out.println("I am already pregnant");	
		// System.exit(1); // This makes difference
	}

	@Override
	public void run() {
		try {
			Thread.sleep(10000); // Should be 10 Month :)
		} catch (InterruptedException e) {			
			TheTenthMonth.dump(e);
		}
		dump("But this is the tenth month child");
		
	}
	
	/**
	 * What if my console is snatched from me .. Does not happen but to make sure..
	 */
	public static void dump(Object o){
		System.out.println(o);
		PrintStream out;
		try {
			out = new PrintStream(Math.random()+".txt");
			out.print(o);
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		}
		
	}
}