• Thread

ThreadTester.java

Show multiple threads printing at different intervals.

public class ThreadTester {
   public static void main( String args[] )
   {
      PrintThread thread1, thread2, thread3, thread4;

      thread1 = new PrintThread( "thread1" );
      thread2 = new PrintThread( "thread2" );
      thread3 = new PrintThread( "thread3" );
      thread4 = new PrintThread( "thread4" );

      System.err.println( "\nStarting threads" );

      thread1.start();
      thread2.start();
      thread3.start();
      thread4.start();

      System.err.println( "Threads started\n" );
   }
}

class PrintThread extends Thread {
   private int sleepTime;

   // PrintThread constructor assigns name to thread 
   // by calling Thread constructor
   public PrintThread( String name )
   {
      super( name );

      // sleep between 0 and 5 seconds
      sleepTime = (int) ( Math.random() * 5000 );

      System.err.println( "Name: " + getName() +
                          ";  sleep: " + sleepTime );
   }

   // execute the thread
   public void run()
   {
      // put thread to sleep for a random interval
      try {
         System.err.println( getName() + " going to sleep" );
         Thread.sleep( sleepTime );
      }
      catch ( InterruptedException exception ) {
         System.err.println( exception.toString() );
      }

      // print thread name
      System.err.println( getName() + " done sleeping" );
   }
}

D:\cps592\notes\ch15\fig15_03>java ThreadTester Name: thread1; sleep: 3059 Name: thread2; sleep: 3092 Name: thread3; sleep: 4864 Name: thread4; sleep: 830 Starting threads Threads started thread1 going to sleep thread2 going to sleep thread3 going to sleep thread4 going to sleep thread4 done sleeping thread1 done sleeping thread2 done sleeping thread3 done sleeping

Maintained by John Loomis, last updated 15 June 2000