Java多线程之并发锁

这是自JDK5.0开始提供的Java并发包里面的类

下面是关于Java并发锁的测试代码

packagecom.jadyer.thread.lock;

importjava.util.concurrent.locks.Lock;
importjava.util.concurrent.locks.ReentrantLock;

/**
*LockTest
*@author宏宇
*@createMar1,20127:12:04PM
*/
publicclassLockTest{
publicstaticvoidmain(String[]args){
FoodCenterfc=newFoodCenter();
newThread(newThreadDog(fc,"Itisdog`sfood")).start();
newThread(newThreadPig(fc,"Itispig`sfood")).start();
}
}


classThreadDogimplementsRunnable{
privateFoodCenterfc;
privateStringfoodname;
publicThreadDog(FoodCenterfc,Stringfoodname){
this.fc=fc;
this.foodname=foodname;
}
@Override
publicvoidrun(){
while(true){
try{
Thread.sleep(1000);
}catch(InterruptedExceptione){
e.printStackTrace();
}
fc.getFood(foodname);
}
}
}


classThreadPigimplementsRunnable{
privateFoodCenterfc;
privateStringfoodname;
publicThreadPig(FoodCenterfc,Stringfoodname){
this.fc=fc;
this.foodname=foodname;
}
@Override
publicvoidrun(){
while(true){
try{
Thread.sleep(2000);
}catch(InterruptedExceptione){
e.printStackTrace();
}
fc.getFood(foodname);
}
}
}


/**
*@see=========================================================================================
*@seejava.util.concurrent是JDK5.0开始提供的Java并发包，其子包locks是专门用于处理线程锁的
*@seejava.util.concurrent.locks.Lock较synchronized关键字比，有一个最大的区别，那就是
*@seeLock可以比synchronized更细粒度的控制锁，体现在try{...}finally{mylock.unlock();}
*@see=========================================================================================
*@seeLock有点像公共厕所的门闩，只有正在使用厕所的人，把门闩打开出来了，其它人才可以使用公厕
*@seeLock比传统线程模型中的synchronized方式更加面向对象。与生活中的锁类似，锁本身也应该是一个对象
*@see两个线程执行的代码片段要实现同步互斥的效果，那么这两个线程所使用的必须是同一个Lock对象
*@see并且，锁应该位于待操作的资源类的内部方法中，而非线程代码中
*@see=========================================================================================
*/
classFoodCenter{
Lockmylock=newReentrantLock();//创建一个锁
publicvoidgetFood(Stringname){
intlen=name.length();
mylock.lock();//上锁
try{
for(inti=0;i<len;i++){
System.out.print(name.charAt(i));
}
System.out.println();
}finally{
mylock.unlock();//解锁
}
}
}