1 public class Static { 2  3     public static void main(String[] args) { 4         A a = new A(); 5         a.a();// a 6  7         A a1 = new B(); 8         a1.a();// a 9         B a2 = new B();10         a2.a();// b11     }12 13 }14 15 class A {16 17     public static void a() {18         System.out.println("a");19 20     }21 }22 23 class B extends A {24     // 不能@Override,编译器会报错25     public static void a() {26         System.out.println("b");27     }28 29 } annotation:类的加载情况以后会写到