consumer.java

learning java的源代码。书中每个实例都有相关的代码example。

//file: Consumer.java
import java.util.Vector;

class Producer extends Thread {
    static final int MAXQUEUE = 5;
    private Vector messages = new Vector(  );

    public void run(  ) {
        try {
            while ( true ) {
                putMessage(  );
                sleep( 1000 );
            }
        }
        catch( InterruptedException e ) { }
    }

    private synchronized void putMessage(  )
      throws InterruptedException {

        while ( messages.size(  ) == MAXQUEUE )
            wait(  );
        messages.addElement( new java.util.Date().toString(  ) );
        notify(  );
    }

    // called by Consumer
    public synchronized String getMessage(  )
      throws InterruptedException {
        notify(  );
        while ( messages.size(  ) == 0 )
            wait(  );
        String message = (String)messages.firstElement(  );
        messages.removeElement( message );
        return message;
    }
}  // end of class Producer

public class Consumer extends Thread {
    Producer producer;

    Consumer(Producer p) {
        producer = p;
    }

    public void run(  ) {
        try {
            while ( true ) {
                String message = producer.getMessage(  );
                System.out.println("Got message: " + message);
                sleep( 2000 );
            }
        }
        catch( InterruptedException e ) { }
    }

    public static void main(String args[]) {
        Producer producer = new Producer(  );

        producer.start(  );
        new Consumer( producer ).start(  );
    }
}