Producer consumer for J2SE 1.5 using concurrent


/*
 * Copyright (c) Ian F. Darwin, http://www.darwinsys.com/, 1996-2002.
 * All rights reserved. Software written by Ian F. Darwin and others.
 * $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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 * Java, the Duke mascot, and all variants of Sun's Java "steaming coffee
 * cup" logo are trademarks of Sun Microsystems. Sun's, and James Gosling's,
 * pioneering role in inventing and promulgating (and standardizing) the Java 
 * language and environment is gratefully acknowledged.
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 * The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for
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import java.util.*;
import java.io.*;
import java.util.concurrent.*;

/** Producer-Consumer in Java, for J2SE 1.5 using concurrent.
 */
public class ProdCons15 {

  protected boolean done = false;

  /** Inner class representing the Producer side */
  class Producer implements Runnable {

    protected BlockingQueue queue;

    Producer(BlockingQueue theQueue) { this.queue = theQueue; }

    public void run() {
      try {
        while (true) {
          Object justProduced = getRequestFromNetwork();
          queue.put(justProduced);
          System.out.println("Produced 1 object; List size now " + queue.size());
          if (done) {
            return;
          }
        }
      } catch (InterruptedException ex) {
        System.out.println("Producer INTERRUPTED");
      }
    }

    Object getRequestFromNetwork() {  // Simulation of reading from client
      try {
          Thread.sleep(10); // simulate time passing during read
      } catch (InterruptedException ex) {
         System.out.println("Producer Read INTERRUPTED");
      }
      return(new Object());
    }
  }

  /** Inner class representing the Consumer side */
  class Consumer implements Runnable {
    protected BlockingQueue queue;

    Consumer(BlockingQueue theQueue) { this.queue = theQueue; }

    public void run() {
      try {
        while (true) {
          Object obj = queue.take();
          int len = queue.size();
          System.out.println("List size now " + len);
          process(obj);
          if (done) {
            return;
          }
        }
      } catch (InterruptedException ex) {
          System.out.println("CONSUMER INTERRUPTED");
      }
    }

    void process(Object obj) {
      // Thread.sleep(xxx) // Simulate time passing
      System.out.println("Consuming object " + obj);
    }
  }

  ProdCons15(int nP, int nC) {
    BlockingQueue myQueue = new LinkedBlockingQueue();
    for (int i=0; i<nP; i++)
      new Thread(new Producer(myQueue)).start();
    for (int i=0; i<nC; i++)
      new Thread(new Consumer(myQueue)).start();
  }

  public static void main(String[] args)
  throws IOException, InterruptedException {

    // Start producers and consumers
    int numProducers = 4;
    int numConsumers = 3;
    ProdCons15 pc = new ProdCons15(numProducers, numConsumers);

    // Let the simulation run for, say, 10 seconds
    Thread.sleep(10*1000); 

    // End of simulation - shut down gracefully
    pc.done = true;
  }
}
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Producer consumer for J2SE 1.5 using concurrent : Producer Consumer « Threads « Java

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