Java ReentrantLock使用

package com.wkcto.lock.reentrant;

import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/**
 * Lock锁的基本使用
 */
public class Test02 {
    //定义显示锁
    static Lock lock = new ReentrantLock();
    //定义方法
    public static void sm(){
        //先获得锁
        lock.lock();
        //for循环就是同步代码块
        for (int i = 0; i < 100; i++) {
            System.out.println(Thread.currentThread().getName() + " -- " + i);
        }
        //释放锁
        lock.unlock();
    }

    public static void main(String[] args) {
        Runnable r = new Runnable() {
            @Override
            public void run() {
                sm();
            }
        };
        //启动三个线程
        new Thread(r).start();
        new Thread(r).start();
        new Thread(r).start();
    }
}

package com.wkcto.lock.reentrant;

import java.util.Random;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/**
 * 使用Lock锁同步不同方法中的同步代码块
 */
public class Test03 {
    static Lock lock = new ReentrantLock();         //定义锁对象
    public static void sm1(){
        //经常在try代码块中获得Lock锁, 在finally子句中释放锁
        try {
            lock.lock();        //获得锁
            System.out.println(Thread.currentThread().getName() + "-- method 1 -- " + System.currentTimeMillis() );
            Thread.sleep(new Random().nextInt(1000));
            System.out.println(Thread.currentThread().getName() + "-- method 1 -- " + System.currentTimeMillis() );
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();          //释放锁
        }
    }

    public static void sm2(){
        try {
            lock.lock();        //获得锁
            System.out.println(Thread.currentThread().getName() + "-- method 22 -- " + System.currentTimeMillis() );
            Thread.sleep(new Random().nextInt(1000));
            System.out.println(Thread.currentThread().getName() + "-- method 22 -- " + System.currentTimeMillis() );
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();          //释放锁
        }
    }

    public static void main(String[] args) {
        Runnable r1 = new Runnable() {
            @Override
            public void run() {
                sm1();
            }
        };
        Runnable r2 = new Runnable() {
            @Override
            public void run() {
                sm2();
            }
        };

        new Thread(r1).start();
        new Thread(r1).start();
        new Thread(r1).start();
        new Thread(r2).start();
        new Thread(r2).start();
        new Thread(r2).start();
    }
}