reader.java

21天学通java的示例程序源代码

//Reader.java

package com.wrox.syncserver;

import java.util.Vector;

public class Reader extends Thread {

  // The queue is the communication channel between
  // this reader and the writer.
  private Vector queue;

  // A name so we can tell the readers apart.
  private String name;

  /**
   * Create a reader to read objects from a queue.
   * @param queue Contains the flow of objects from the writer.
   * @param name A name so we can distinguish readers.
   */
  public Reader(Vector queue, String name) {
    this.queue = queue;
    this.name = name;
  }

  public void run() {
    for (; ; ) {
      synchronized (queue) {   // acquire the monitor
        while (queue.isEmpty()) {
          try {
            queue.wait();      // releases the monitor
          } catch (InterruptedException ex) {

            // Nothing to do here. If the queue is empty,
            // might as well go back to waiting.
          } 
        } 

        // At this point the monitor has been re-acquired
        Object o = queue.remove(0);
        System.out.println(name + " got job number: " + o);
      }                        // release the monitor at the end of the synchronized block
     } 
  } 
}