// Join.java

// Introducing the sleep() and join() methods.
// Note that the interleaving of thread outputs is not quite perfect.

// by Kip Irvine
// Updated 1/21/2003

import java.lang.Thread;

class MessageThread implements Runnable 
{
	public MessageThread( String msg )
	{
		message = msg;
	}	

	public void run( )
	{
   		try 
   		{
			for( int i = 0; i < 20; i++ )
			{
				System.out.println( message + i );
    			Thread.currentThread( ).sleep( 100 );
    		}
    	}	
    	catch( InterruptedException	e ) 
    	{
    	 
    	}
  	} 
  private String message;
}

class ThreadDemo 
{
	public static void main( String[] args ) 
	{
     	Thread t1 = new Thread ( new MessageThread ( "Thread1: " ) );	
     	Thread t2 = new Thread ( new MessageThread ( "Thread2: " ) );		
     	t1.start( );
     	t2.start( );
     
     	// comment out this try-catch block to see how the program's behavior changes	
     	try {
     		t1.join( );		// t1.join( 1000 ) to wait at most 1000 milliseconds
     		t2.join( );
     	}
     	catch( InterruptedException	e ) { }
     	
		System.out.println( "All threads have finished" );
	}
}