public?class?Main?{

????public?static?void?main(String[]?args)?{
????????test?test?=?new?test();
????????test.xxx(new?zi());


????}
}

class?fu{
????public?void?x(){
????????System.out.println("我是父");
????}
}

class?zi?extends?fu{
????public?void?x(){
????????System.out.println("我重寫了父類的x方法");
????}
????public?void?xx(){
????????System.out.println("我是子");
????}
}

class?test{
????public?void?xxx(fu?xxx){
????????xxx.x();
????}
}