云南大学软件学院 实验报告 课程： Java 程序设计实验 学期： 2012-2013 学年 第一学期 任课教师： 陆歌浩 专业： 软件工程 学号： 20101120007 序号： 12 姓名： 孙金文 成绩： 实验 8 接口 一、实验目的 练习 Java 中接口概念的应用。 二、实验内容 Program 1 Create an interface called Playing. The interface has an abstract method called play(). Create classes called Child, Musician and Actor that implement Playing. Create a program that demonstrates the use of the classes. Playing.java Child.java Musician.java Actor.java UsePlaying.java Sample Output: I am a child and I am playing a game I am a musician and I am playing a song I am an actor and I am playing a part 实验代码： package edu.ynu.lab8; import javax.swing.JOptionPane; interface Playing{ public abstract String play(); //抽象函数 } class Child implements Playing { public String play() //实现抽象函数 { String str = "I am a child and I am playing a game."; return str; } } 1 

class Musician implements Playing { public String play() { String str = "I am a musician and I am playing a song."; return str; } } class Actor implements Playing { public String play() { String str = "I am an actor and I am playing a part."; return str; } } public class UsePlaying { public static void main(String[] args) { Child child = new Child(); Musician musician = new Musician(); Playing actor = new Actor(); String achild = child.play(); String amusician = musician.play(); String aactor = actor.play(); JOptionPane.showMessageDialog(null,achild+ "\n"+ amusician+"\n" + aactor+"\n","执行结果(孙金文——20101120007)", JOptionPane.PLAIN_MESSAGE); } } 运行截图： 2