接口与继承：方法覆盖（super）

//父类Parent
class Parent{
    int x;
    int y;
    Parent()
    {
        x = 0;
        y = 0;
    }
    public void Set(int a,int b)
    {
        x = a;
        y = b;
    }
}
//子类Child继承了Parent
class Child extends Parent{
    int z;
    Child()
    {
        super();//使用父类的构造方法初始化
        z = 0;
    }
    public void Set(int a,int b)//与父类相同的方法
    {
        x = a;
        y = b;
        z = a + b;
    }
    public void Show()
    {
        System.out.println("初始值");
        System.out.println("x = "+ x +"  y = " + y + "  z = " + z);
        System.out.println("调用父类的Set方法Set(1,2)");
        super.Set(1,2);
        System.out.println("x = "+ x +"  y = " + y + "  z = " + z);
        
        System.out.println("调用子类的Set方法Set(1,2)");
        Set(1,2);
        System.out.println("x = "+ x +"  y = " + y + "  z = " + z);
    }
    
}

public class Test {
    public static void main(String args[])
    {
        Child c = new Child();
        c.Show();
    }

}