java 读写锁 java5特有的 多线程

import java.util.concurrent.ExecutorService; 
import java.util.concurrent.Executors; 
import java.util.concurrent.locks.ReadWriteLock; 
import java.util.concurrent.locks.ReentrantReadWriteLock; 

/** 
* Java线程：锁 
* 
* @author leizhimin 2009-11-5 10:57:29 
*/ 
public class Test { 
        public static void main(String[] args) { 
                //创建并发访问的账户 
                MyCount myCount = new MyCount("95599200901215522", 10000); 
                //创建一个锁对象 
                ReadWriteLock lock = new ReentrantReadWriteLock(false); 
                //创建一个线程池 
                ExecutorService pool = Executors.newFixedThreadPool(2); 
                //创建一些并发访问用户，一个信用卡，存的存，取的取，好热闹啊 
                User u1 = new User("张三", myCount, -4000, lock, false); 
                User u2 = new User("张三他爹", myCount, 6000, lock, false); 
                User u3 = new User("张三他弟", myCount, -8000, lock, false); 
                User u4 = new User("张三", myCount, 800, lock, false); 
                User u5 = new User("张三他爹", myCount, 0, lock, true); 
                //在线程池中执行各个用户的操作 
                pool.execute(u1); 
                pool.execute(u2); 
                pool.execute(u3); 
                pool.execute(u4); 
                pool.execute(u5); 
                //关闭线程池 
                pool.shutdown(); 
        } 
} 

/** 
* 信用卡的用户 
*/ 
class User implements Runnable { 
        private String name;                //用户名 
        private MyCount myCount;        //所要操作的账户 
        private int iocash;                 //操作的金额，当然有正负之分了 
        private ReadWriteLock myLock;                //执行操作所需的锁对象 
        private boolean ischeck;        //是否查询 

        User(String name, MyCount myCount, int iocash, ReadWriteLock myLock, boolean ischeck) { 
                this.name = name; 
                this.myCount = myCount; 
                this.iocash = iocash; 
                this.myLock = myLock; 
                this.ischeck = ischeck; 
        } 

        public void run() { 
                if (ischeck) { 
                        //获取读锁 
                        myLock.readLock().lock(); 
                        System.out.println("读：" + name + "正在查询" + myCount + "账户，当前金额为" + myCount.getCash()); 
                        //释放读锁 
                        myLock.readLock().unlock(); 
                } else { 
                        //获取写锁 
                        myLock.writeLock().lock(); 
                        //执行现金业务 
                        System.out.println("写：" + name + "正在操作" + myCount + "账户，金额为" + iocash + "，当前金额为" + myCount.getCash()); 
                        myCount.setCash(myCount.getCash() + iocash); 
                        System.out.println("写：" + name + "操作" + myCount + "账户成功，金额为" + iocash + "，当前金额为" + myCount.getCash()); 
                        //释放写锁 
                        myLock.writeLock().unlock(); 
                } 
        } 
} 

/** 
* 信用卡账户，可随意透支 
*/ 
class MyCount { 
        private String oid;         //账号 
        private int cash;             //账户余额 

        MyCount(String oid, int cash) { 
                this.oid = oid; 
                this.cash = cash; 
        } 

        public String getOid() { 
                return oid; 
        } 

        public void setOid(String oid) { 
                this.oid = oid; 
        } 

        public int getCash() { 
                return cash; 
        } 

        public void setCash(int cash) { 
                this.cash = cash; 
        } 

        @Override 
        public String toString() { 
                return "MyCount{" + 
                                "oid='" + oid + '\'' + 
                                ", cash=" + cash + 
                                '}'; 
        } 
}

运行结果

写：张三正在操作MyCount{oid='95599200901215522', cash=10000}账户，金额为-4000，当前金额为10000
写：张三操作MyCount{oid='95599200901215522', cash=6000}账户成功，金额为-4000，当前金额为6000
写：张三他弟正在操作MyCount{oid='95599200901215522', cash=6000}账户，金额为-8000，当前金额为6000
写：张三他弟操作MyCount{oid='95599200901215522', cash=-2000}账户成功，金额为-8000，当前金额为-2000
写：张三正在操作MyCount{oid='95599200901215522', cash=-2000}账户，金额为800，当前金额为-2000
写：张三操作MyCount{oid='95599200901215522', cash=-1200}账户成功，金额为800，当前金额为-1200
读：张三他爹正在查询MyCount{oid='95599200901215522', cash=-1200}账户，当前金额为-1200
写：张三他爹正在操作MyCount{oid='95599200901215522', cash=-1200}账户，金额为6000，当前金额为-1200
写：张三他爹操作MyCount{oid='95599200901215522', cash=4800}账户成功，金额为6000，当前金额为4800

Process finished with exit code 0