java并发之Lock接口的深入讲解

//  加锁
lock.lock();
try{
    //处理任务
}catch(Exception ex){
​
}finally{
    //释放锁  （锁的释放一般放入到finally块中进行，这样保证了总会对锁信息进行释放）
    lock.unlock();   
}

Lock lock = ...;
if(lock.tryLock()) {
     try{
         //处理任务
     }catch(Exception ex){
​
     }finally{
         lock.unlock();   //释放锁
     } 
}else {
    //如果不能获取锁，则直接做其他事情
}

public void method() throws InterruptedException {
    lock.lockInterruptibly();
    try {  
     //.....
    }
    finally {
        lock.unlock();
    }  
}

public class LockInterruptibly implements Runnable {
​
    private Lock lock = new ReentrantLock();
public static void main(String[] args) {
    LockInterruptibly lockInterruptibly = new LockInterruptibly();
    Thread thread0 = new Thread(lockInterruptibly);
    Thread thread1 = new Thread(lockInterruptibly);
    thread0.start();
​
    try {
        Thread.sleep(2000);
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
    thread1.start();
    thread1.interrupt();
}
   // 任务执行逻辑
    @Override
    public void run() {
        System.out.println(Thread.currentThread().getName() + "尝试获取锁");
        try {
            lock.lockInterruptibly();
            try {
                System.out.println(Thread.currentThread().getName() + "获取到了锁");
                Thread.sleep(5000);
            } catch (InterruptedException e) {
                System.out.println(Thread.currentThread().getName() + "睡眠期间被中断了");
            } finally {
                lock.unlock();
                System.out.println(Thread.currentThread().getName() + "释放了锁");
            }
        } catch (InterruptedException e) {
            System.out.println(Thread.currentThread().getName() + "获得锁期间被中断了");
        }
    }
}
​

// 实例代码 
public class LockDemo  implements Runnable{
  static Lock lock1 = new ReentrantLock();
    @Override
    public void run() {
        // 分别演示 lock,trylock区别
        // lock1.lock();
        lock1.tryLock();
        System.out.println("线程 " + Thread.currentThread().getName() + " 获取到锁信息 ");
    }
    
    
    public static void main(String[] args) throws InterruptedException {
        LockDemo r1 = new LockDemo();
        LockDemo r2 = new LockDemo();
        r1.flag = true;
        r2.flag = false;
        Thread t1 = new Thread(r1);
        Thread t2 = new Thread(r2);
​
        t1.start();
        Thread.sleep(1000);
        // 中断
        t2.start();
        t2.interrupt();
    }
}
​