import java.util.*;
 
public class TalkingThreads 
{
   public static void main( String [] args )
   {
      Listener listener = new Listener();
      Talker talker = new Talker(listener);
      talker.start();
      listener.start();
   }
 
}
class Talker extends Thread
{
   String [] thingsToSay = { "Hi", "How's it goin'?", "Hey there",
                             "How do?", "Howdy", "Felicitations", 
                             "Hiya", "Hey", "Yo", "Wutup?", "Hola",
                             "Bon Jour", "Guten Tag", "Previet" };
   private Listener listener;
   private static Random randy = new Random();
 
   public Talker( Listener l )
   {
      listener = l;
   }
 
   public void run()
   {
      long endTime = System.currentTimeMillis() + 5*1000 + randy.nextInt(10*1000);
 
      while( System.currentTimeMillis() < endTime  )
      {
         try 
         {
            Thread.sleep( randy.nextInt( 1000 ) + 100 );
         }
         catch( InterruptedException ie )
         {
            System.out.println("Leave me alone, I'm trying to sleep.");
         }
 
         talk( listener );
      }
      System.out.println( "Comment from Talker:  I've had enough of this conversation." );
   }
 
   public void talk( Listener l )
   {
      String said = thingsToSay[randy.nextInt( thingsToSay.length )];
      l.listen( said );
      System.out.println( "Comment from Talker:  I just said:  " + said );
   }
}
 
class Listener extends Thread
{
   private LinkedList messageQueue = new LinkedList();
   private static Random randy = new Random();
 
   synchronized public void listen( String msg )
   {
      messageQueue.add(msg);
   }
 
   synchronized public void echoMessage()
   {
      System.out.print( "Comment from Listner: " );
      if( messageQueue.isEmpty() )
         System.out.println( "Haven't heard much lately." );
      else
         System.out.println( "I just heard: " + (String)messageQueue.removeFirst() );
   }
 
   public void run()
   {
      // Only pay attention for a minute:
      long endTime = System.currentTimeMillis() + 7*1000 + randy.nextInt(15*1000);
 
      while( System.currentTimeMillis() < endTime  )
      {
         try
         {
            Thread.sleep( randy.nextInt( 1200 ) );
         }
         catch( InterruptedException ie )
         {
            System.out.println("Leave me alone, I'm trying to sleep.");
         }
 
         echoMessage();
      }
      System.out.println( "Comment from Listner: That's what I was going to say." );
   }
 
}