Java锁示例

以下是一段多线程锁机制示例代码：

package lock;

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

public class ThreadTest {
    private int j;
    private Lock lock = new ReentrantLock();
    
    public static void main(String[] args){
        ThreadTest tt = new ThreadTest();
        for (int i=0; i<2; i++){
            new Thread(tt.new Adder()).start();
            new Thread(tt.new Subtractor()).start();
        }
    }
    
    private class Subtractor implements Runnable{
        public void run(){
            while (true){
                
                lock.lock();
                
                try{
                    System.out.println("j--=" + j--);
                }finally{
                    lock.unlock();
                }
            }
        }
    }
    
    private class Adder implements Runnable{
        public void run(){
            while(true){
                
                lock.lock();
                try{
                    System.out.println("j++" + j++);
                }finally{
                    lock.unlock();
                }
            }
        }
    }
}