synchronized method in derived class

Question

如果基类A有一个“public synchronized void method（）{}”，它没有被派生类B覆盖，那么将使用的是什么（即它将是派生类对象还是基类对象）访问B类中的synchronized方法？

Answer 1

There is no "base class object".

synchronized methods lock on the instance they're called on.

Answer 2

public synchronized void method() {  
    ...
};

is just the same as

public void method() {  
    synchronized(this){
        ...
    }
};

And for a super-method this means an object of class B . So the lock will be on an instance of the object B .