多线程顺序打印

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;
}

}

}