/*

  * 1.ReadWriterLock ： 读写锁

  *

  * 写写 /读写 需要 “互斥”

  * 读读 不需要互斥

  * */

 public class TestReadWriteLock {

     public static void main(String[] args) {

         //匿名内部类 使用外部的参数 需要加上 final （1.8之后就不需要了 ，但是也不能修改）

         //这和外部参数的生命周期有关

          final ReadWriteLockThread lt = new ReadWriteLockThread();

         //创建一个 ‘写’ 线程

         new Thread(new Runnable() {

             @Override

             public void run() {

                 lt.write(10);

             }

         },"write").start();

         ////创建100个 ‘读’ 线程

         for(int i = 0;i<100;i++) {

             new Thread(new Runnable() {

                 @Override

                 public void run() {

                     lt.read();

                 }

             },"read").start();

         }

     }

 }

 class ReadWriteLockThread {

     private int number = 1;

     private ReadWriteLock lock = new ReentrantReadWriteLock();

     public void read() {

         lock.readLock().lock();

         try {

             System.out.println(number);

         } finally {

             lock.readLock().unlock();

         }

     }

     public void write(int number) {

         lock.writeLock().lock();

         try {

             System.out.println(this.number);

             this.number = number;

         } finally {

             lock.writeLock().unlock();

         }

     }

 }