JDK1.5——synchronized升级版（显示的Lock操作）

import java.util.concurrent.locks.*;
/*
JDK1.5 中提供了多线程升级解决方案。
将同步Synchronized替换成显示Lock操作。
将Object中的wait，notify notifyAll，替换了Condition对象。
该对象可以Lock锁 进行获取。
该示例中，实现了本方只唤醒对方操作。

Lock:替代了Synchronized
    lock 
    unlock
    newCondition()

Condition：替代了Object wait notify notifyAll
    await();
    signal();
    signalAll();
*/
class LockDemo
{
    public static void main(String[] args) 
    {
        Resource r = new Resource();

        producer pro = new producer(r);
        consumer con = new consumer(r);

        Thread t1 = new Thread(pro);
        Thread t2 = new Thread(pro);
        Thread t3 = new Thread(con);
        Thread t4 = new Thread(con);

        t1.start();
        t2.start();
        t3.start();
        t4.start();

//        Thread t11 = new Thread(pro);
//        Thread t22 = new Thread(pro);
//        Thread t33 = new Thread(con);
//        Thread t44 = new Thread(con);

//        t11.start();
//        t22.start();
//        t33.start();
//        t44.start();
    }
}

//资源类
class Resource
{
    private String name;
    private int count = 1;
    private boolean flag = false;
    
    //设置锁对象
    private Lock lock = new ReentrantLock();
    //设置Condition对象，用于对线程进行可控的休眠唤醒操作
    Condition condition_pro = lock.newCondition();//对生产者操作
    Condition condition_con = lock.newCondition();//对消费者操作
    
    //设置资源名称
    public void set(String name)
    {
        lock.lock();
        try
        {
            while (flag)
            {
                condition_pro.await();
            }
            this.name = name+"---"+count++;
            System.out.println(Thread.currentThread().getName()+"..."+name);
            flag = true;
            condition_con.signal();
        }
        catch (Exception e)
        {
        }
        finally
        {
            lock.unlock();//将释放锁的动作放到finally中使其一定会被执行。
        }
    }

    //获取资源（消费资源）
    public void get()
    {
        try
        {
            lock.lock();
            while (!flag)
            {
                condition_con.await();
            }
            System.out.println(Thread.currentThread().getName()+".........."+name);
            flag = false;
            condition_pro.signal();
        }
        catch (Exception e)
        {
        }
        finally
        {
            lock.unlock();
        }
        
    }
}
//生产者类
class producer implements Runnable
{
    private Resource r;
    producer(Resource r)
    {
        this.r = r;
    }

    public void run()
    {
        while (true)
        {
            r.set("+商品+");
        }
    }
}
//消费者类
class consumer implements Runnable
{
    private Resource r;
    consumer(Resource r)
    {
        this.r = r;
    }

    public void run()
    {
        while (true)
        {
            r.get();
        }
    }
}