1.同步

• 使用ReentrantLock类的lock()和unlock()方法进行同步

  • 2.通信

• 使用ReentrantLock类的newCondition()方法可以获取Condition对象

• 需要等待的时候使用Condition的await()方法, 唤醒的时候用signal()方法

• 不同的线程使用不同的Condition, 这样就能区分唤醒的时候找哪个线程了

/**     * @param args     */    public static void main(String[] args) {        final Printer3 p = new Printer3();        new Thread() {            public void run() {                while(true) {                    try {                        p.print1();                    } catch (InterruptedException e) {                        e.printStackTrace();                    }                }            }        }.start();        new Thread() {            public void run() {                while(true) {                    try {                        p.print2();                    } catch (InterruptedException e) {                        e.printStackTrace();                    }                }            }        }.start();        new Thread() {            public void run() {                while(true) {                    try {                        p.print3();                    } catch (InterruptedException e) {                        e.printStackTrace();                    }                }            }        }.start();    }}class Printer3 {    private ReentrantLock r = new ReentrantLock();    private Condition c1 = r.newCondition();    private Condition c2 = r.newCondition();    private Condition c3 = r.newCondition();    private int flag = 1;    public void print1() throws InterruptedException {                                  r.lock();                               //获取锁            if(flag != 1) {                c1.await();            }            System.out.print("黑");            System.out.print("马");            System.out.print("程");            System.out.print("序");            System.out.print("员");            System.out.print("\r\n");            flag = 2;            //this.notify();                        //随机唤醒单个等待的线程            c2.signal();        r.unlock();                             //释放锁    }    public void print2() throws InterruptedException {        r.lock();            if(flag != 2) {                c2.await();            }            System.out.print("传");            System.out.print("智");            System.out.print("播");            System.out.print("客");            System.out.print("\r\n");            flag = 3;            //this.notify();            c3.signal();        r.unlock();    }    public void print3() throws InterruptedException {        r.lock();            if(flag != 3) {                c3.await();            }            System.out.print("i");            System.out.print("t");            System.out.print("h");            System.out.print("e");            System.out.print("i");            System.out.print("m");            System.out.print("a");            System.out.print("\r\n");            flag = 1;            c1.signal();        r.unlock();    }