前言：

      下面的代码是参考网址：http://love3400wind.blog.163.com/blog/static/796308012013117102941831/ , http://blog.csdn.net/liu251/article/details/6227763 做了一点点的改动。

      感谢两位作者！

题目：

有A,B,C三个线程, A线程输出A, B线程输出B, C线程输出C

要求, 同时启动三个线程, 按顺序输出ABC, 循环10次

 

核心要素：

     1，工作线程对象之间的关联。

     2，工作线程的状态修改(前一个线程对象有能力修改后一个线程对象的状态)。

 

示例：

package org.wit.ff.thread;import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;import java.util.concurrent.locks.Condition;import java.util.concurrent.locks.Lock;import java.util.concurrent.locks.ReentrantLock;/** *  * @author F.Fang *  */public class ABCDemo {    private Lock lock = new ReentrantLock();// 通过JDK5中的锁来保证线程的访问的互斥    private Condition condition = lock.newCondition();// 线程协作    public static void main(String[] args) {        ABCDemo abc = new ABCDemo();        // 使用循环可以不局限于只有3个线程 交替, 任意多个都可以.        PrintThread a = abc.new PrintThread("A", true);        PrintThread b = abc.new PrintThread("B", false);        PrintThread c = abc.new PrintThread("C", false);        a.setNext(b);        b.setNext(c);        c.setNext(a);        ExecutorService executor = Executors.newFixedThreadPool(3);// 通过线程池执行        for (int i = 0; i < 3; i++) {            executor.execute(a);            executor.execute(b);            executor.execute(c);        }        executor.shutdown();//关闭线程池    }    class PrintThread implements Runnable {        private String name;        private PrintThread next;        private boolean execute;        public PrintThread(String name, boolean execute) {            this.name = name;            this.execute = execute;        }        public PrintThread(String name, PrintThread next, boolean execute) {            this.name = name;            this.next = next;            this.execute = execute;        }        public void run() {            lock.lock();            try {                while (true) {                    if (execute) {                        // 执行当前业务                        print();                        // 当前任务执行完成后 改变执行状态为false                        execute = false;                        // 将下一个相邻任务状态设置为true                        next.setExecute(true);                        try {                            Thread.sleep(100);                        } catch (InterruptedException e) {                            e.printStackTrace();                        }                        // 通知其它任务.                        condition.signalAll();                        break;                    } else {                        try {                            // 若非执行状态 即等待.                            condition.await();                        } catch (InterruptedException e) {                            e.printStackTrace();                        }                    }                }            } finally {                lock.unlock();            }        }        public void print() {            System.out.println(name);        }        public void setExecute(boolean execute) {            this.execute = execute;        }        public void setNext(PrintThread next) {            this.next = next;        }    }}