public class Lock {
    //验证synchronized写在普通方法上的锁所住的是类对象
    public synchronized  void method1(){
        try{
            System.out.println("invoke in method1()");
            Thread.sleep(5000);
        }catch (InterruptedException e){
        }
    }
    public void method2(){
        Object o = new Object();
        System.out.println("invoke in method2()");
        synchronized (this){
            System.out.println("now invoke in method2():synchronized block");
        }
    }
//    method3、4验证加载静态方法上的synchronized锁住的是该类的.class对象
    public synchronized static void method3(){
        try{
            System.out.println("invoke in method3()");
            Thread.sleep(5000);
        }catch (InterruptedException e){
        }
    }
    public static void method4(){
        System.out.println("invoke in method4()");
        synchronized (Lock.class){
            System.out.println("now invoke in method4():synchronized block");
        }
    }
    public static void main(String[] args){
        Lock l = new Lock();
//        注释的两组为同一组实验
//        new Thread(()->l.method1()).start();
//        new Thread(()->l.method2()).start();
//        未注释的两组为同一组实验
        new Thread(()->method3()).start();
        new Thread(()->l.method4()).start();
//        验证语法基于JDK8，低于JDK8的版本可写成如下形式
//        new Thread(){
//            @Override
//            public void run() {
////             你的代码逻辑，如：
//                l.method1();
//            }
//        }.start();
    }
}