MyThread.java

package join;

import java.util.Random;

public class MyThread extends Thread {
	private Random rnd;

	MyThread(Random r) {
		rnd = r;
	}

	public void run() {
		int seconds = rnd.nextInt(10) + 1;

		System.out.println("A thread started!");

		try
		{
			Thread.sleep(seconds * 1000);
		}
		catch(Exception ex)
		{
			ex.printStackTrace();
		}

		System.out.println("A thread died!");

	}

}