inherit

继承父类的实例方法是覆盖，而且继承静态方法则是隐藏。

隐藏意味着，你还可以调用到父类的被隐藏的方法。

Instance Methods

An instance method in a subclass with the same signature (name, plus the number and the type of its parameters) and return type as an instance method in the superclass overrides the superclass's method.

Class Methods

If a subclass defines a class method with the same signature as a class method in the superclass, the method in the subclass hides the one in the superclass.

 

The distinction between hiding and overriding has important implications. The version of the overridden method that gets invoked is the one in the subclass. The version of the hidden method that gets invoked depends on whether it is invoked from the superclass or the subclass.

 

例子：

public class Animal {
    public static void testClassMethod() {
        System.out.println("The class" + " method in Animal.");
    }
    public void testInstanceMethod() {
        System.out.println("The instance " + " method in Animal.");
    }
}

 

public class Cat extends Animal {
    public static void testClassMethod() {
        System.out.println("The class method" + " in Cat.");
    }
    public void testInstanceMethod() {
        System.out.println("The instance method" + " in Cat.");
    }

    public static void main(String[] args) {
        Cat myCat = new Cat ();
	myCat.testClassMethod();  
        Animal myAnimal = myCat;
        myAnimal.testClassMethod();
        Animal.testClassMethod();
        myAnimal.testInstanceMethod();
        Cat.testClassMethod();
 }
}

  输出结果 是：

The class method in Cat.
The class method in Animal.
The class method in Animal.
The instance method in Cat.
The class method in Cat.