大家提供自己的参考下，看看大家如何修改的。
根据提供的主程序修改程序，定义不同的行为类。 主程序中Say and Sing 不是String。
比如 say 和 sing 各定义为类。看看大家发挥，
根据这个主程序：谢谢
- Java code
..... Person father = new Father(); father.setContent("How are you"); father.act(sing); Mother mother = new Mother(); mother.act(say);....修改如下程序：
- Java code
public class PloyTest1{ public void say(Person person) { person.say(); } public void sing(Person person) { person.sing(); } public static void main(String[] args) { PloyTest1 test = new PloyTest1(); Person person = new Father(); // test.say(person); test.sing(person); Mother mother = new Mother(); test.say(mother); } } //class Person abstract class Person{ /*public void say() { System.out.println("person is saying"); }*/ /*public void sing() { // TODO Auto-generated method stub System.out.println(""); }*/ public abstract void say(); public void sing(){}} class Father extends Person{ public void say() { System.out.println("father is saying: How are you?"); } @Override public void sing() { // TODO Auto-generated method stub System.out.println("father sing: how are you"); }} class Mother extends Person{ public void say() { System.out.println("mother is saying: I am fine"); } /*@Override public void sing() { // TODO Auto-generated method stub }*/}------解决方案--------------------
主程序有问题，就算sing和say是类，也不可能直接用类当参数，要么是sing.class之类的，要么就是new一个sing对象再当参数传入
如果sing和say是对象，比如这段主程序之前定义 Sing sing = new Sing()之类的，那么很显然，act方法接收的参数就是sing和say的共同父类或超类或接口
所以
可以采用接口
- Java code
interface IMouthAction { void action();}class Sing implement IMouthAction { public void action() {System.out.println("sing");}}class Say implement IMouthAction { public void action() {System.out.println("say");}}abstract class Person { public void act(IMouthAction action) {action.action();}}class Father extends Person {}class Mather extends Person {}public class Main { public static void main(String[] args) { IMouthAction sing = new Sing(); IMouthAction say = new Say(); ... //LZ的主代码部分 }}