用读写锁实现代码

用读写锁实现代码如下：转载于http://blog.csdn.net/ghsau/article/details/7461369/

 class Data {
     private int data;// 共享数据
     private ReadWriteLock rwl = new ReentrantReadWriteLock();
     public void set(int data) {
         rwl.writeLock().lock();// 取到写锁
         try {
             System.out.println(Thread.currentThread().getName() + "准备写入数据");
             try {
                 Thread.sleep(20);
             } catch (InterruptedException e) {
                 e.printStackTrace();
             }
             this.data = data;
             System.out.println(Thread.currentThread().getName() + "写入" + this.data);
         } finally {
             rwl.writeLock().unlock();// 释放写锁
         }
     }
     public void get() {
         rwl.readLock().lock();// 取到读锁
         try {
             System.out.println(Thread.currentThread().getName() + "准备读取数据");
             try {
                 Thread.sleep(20);
             } catch (InterruptedException e) {
                 e.printStackTrace();
             }
             System.out.println(Thread.currentThread().getName() + "读取" + this.data);
         } finally {
             rwl.readLock().unlock();// 释放读锁
         }
     }
 }