生产者 消费者 官方例子

package com.oracle.example;

import java.util.Random;

public class Consumer implements Runnable{
	private Drop drop;

	public Consumer(Drop drop) {
		this.drop = drop;
	}

	public void run() {
		Random random = new Random();
		for (String message = drop.take(); !message.equals("DONE"); message = drop.take()) {
			System.out.format("MESSAGE RECEIVED: %s%n", message);
			try {
				Thread.sleep(random.nextInt(5000));
			} catch (InterruptedException e) {
			}
		}
	}

	public static void main(String[] args) {
		Drop drop = new Drop();
		(new Thread(new Producer(drop))).start();
		(new Thread(new Consumer(drop))).start();
	}
}

package com.oracle.example;

public class Drop {
	// Message sent from producer
	// to consumer.
	private String message;
	// True if consumer should wait
	// for producer to send message,
	// false if producer should wait for
	// consumer to retrieve message.
	private boolean empty = true;

	public synchronized String take() {
		// Wait until message is
		// available.
		while (empty) {
			try {
				wait();
			} catch (InterruptedException e) {
			}
		}
		// Toggle status.
		empty = true;
		// Notify producer that
		// status has changed.
		notifyAll();
		return message;
	}

	public synchronized void put(String message) {
		// Wait until message has
		// been retrieved.
		while (!empty) {
			try {
				wait();
			} catch (InterruptedException e) {
			}
		}
		// Toggle status.
		empty = false;
		// Store message.
		this.message = message;
		// Notify consumer that status
		// has changed.
		notifyAll();
	}
}

package com.oracle.example;

import java.util.Random;

public class Producer implements Runnable {
	private Drop drop;

	public Producer(Drop drop) {
		this.drop = drop;
	}

	public void run() {
		String importantInfo[] = { "Mares eat oats", "Does eat oats", "Little lambs eat ivy",
				"A kid will eat ivy too" };
		Random random = new Random();

		for (int i = 0; i < importantInfo.length; i++) {
			System.out.format("MESSAGE PRODUCE: %s%n",importantInfo[i]);
			drop.put(importantInfo[i]);
			try {
				Thread.sleep(random.nextInt(5000));
			} catch (InterruptedException e) {
			}
		}
		drop.put("DONE");
		System.out.format("MESSAGE PRODUCE: %s%n","DONE");
	}
}