面向对象（封装，继承，多态）

水深无声 2022-07-14 14:24 239阅读 0赞

# 封装 #

### 封装一个Teacher和Student类 ###

package com.hz.test;
    
    public class Teacher {
        
    
        private String name;
        private String majorDirection;
        private String teachCourse;
        private int teachAge;
    
        public Teacher() {
            super();
        }
    
        public Teacher(String name,String majorDirection,String teachCourse,int teachAge) {
            this.name = name;
            this.majorDirection = majorDirection;
            this.teachCourse = teachCourse;
            this.teachAge = teachAge;
        }
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
    
        public String getMajorDirection() {
            return majorDirection;
        }
    
        public void setMajorDirection(String majorDirection) {
            this.majorDirection = majorDirection;
        }
    
    
        public String getTeachCourse() {
            return teachCourse;
        }
    
    
        public void setTeachCourse(String teachCourse) {
            this.teachCourse = teachCourse;
        }
    
    
        public int getTeachAge() {
            return teachAge;
        }
    
    
        public void setTeachAge(int teachAge) {
            this.teachAge = teachAge;
        }
    
    
    
    
        public String toString() {
            return "姓名=" + getName() + ", 专业方向=" + getMajorDirection()
                    + ", 所教课程=" + getTeachCourse() + ", 教龄=" + getTeachAge();
        }
    }

Student类

package com.hz.test;
    
    import java.util.Arrays;
    
    /**
     * @author ztw
     *
     */
    public class Student {
        
    
    
        private String name;
        private int age;
        private String[] courses;
        private String interest;
    
        public Student() {
            super();
        }
    
        public Student(String name,int age,String[] courses,String interest) {
            this.name = name;
            this.age = age;
            this.courses = courses;
            this.interest = interest;
        }
        public void setName(String name){
            this.name = name;
        }
        public String getName(){
            return name;
        }
    
        public void setAge(int age){
            if(age<0){
                System.out.println("年龄不能为负值");
            }else{
                this.age = age;
            }
        }
        public int getAge(){
            return age;
        }
    
        public void setCourses(String[] courses){
            this.courses = courses;
        }
        public String getCourses(){
            return Arrays.toString(courses);
        }
    
        public void setInterest(String interest){
            this.interest = interest;
        }
        public String getInterest(){
            return interest;
        }
    
        public String toString() {
            return "姓名=" + getName() + ", 年龄=" + getAge() + ", 课程=" + getCourses()
                    + ", 兴趣=" + getInterest();
        }   
    }

测试类

package com.hz.test;
    
    public class Test {
    
        public static void main(String[] args) {
            String arr[] = {
       "阿斯达","是的","大概","太诱惑"};
            Student stu = new Student("张三",21,arr,"打球");
            Teacher tea = new Teacher("王五","阿斯达","阿斯达",99);
            System.out.println(stu);
            System.out.println(tea);
        }
    }

输出结果：

*  姓名=张三, 年龄=21, 课程=\[阿斯达, 是的, 大概, 太诱惑\], 兴趣=打球
 *  姓名=王五, 专业方向=阿斯达, 所教课程=阿斯达, 教龄=99

# 继承 #

### 定义Play，TaoistPriest，Master，Warrior ###

public class Play {
    
        String main;
    
        public Play(String main) {
            this.main = main;
        }
        public void hitMonster() {
    
            System.out.println(main+"打怪");
        }
    }

/**
     * TaoistPriest:道士
     * @author ztw
     *
     */
    public class TaoistPriest extends Play {
        
    
        {
            System.out.print("我是道士：");
        }
        public TaoistPriest(String main) {
            super(main);
        }
    }

/**
     * Master:法师
     * @author ztw
     *
     */
    public class Master extends Play{
        
    
        {
            System.out.print("我是法师：");
        }
        public Master(String main) {
            super(main);
    
        }
    }

/**
     * Warrior:武士
     * @author ztw
     *
     */
    public class Warrior extends Play{
        
    
        {
            System.out.print("我是武士：");
        }
        public Warrior(String main) {
            super(main);
    
        }
    }

测试类

public class Test {
    
        public static void main(String[] args) {
            TaoistPriest tp = new TaoistPriest("灵魂火符");
            tp.hitMonster();
            Master m = new Master("雷电术");
            m.hitMonster();
            Warrior w = new Warrior("烈火术");
            w.hitMonster();
        }
    }

*  输出结果：

> 我是道士：灵魂火符打怪  
> 我是法师：雷电术打怪  
> 我是武士：烈火术打怪

# 多态 #

### 服务器，客户端交互 ###

#### LoginListener ####

public interface LoginListener {
    
        public void succeed(String msg);
    
        public void failed(String msg);
    }

#### MyLoginListener ####

public class MyLoginListener implements LoginListener{
        
    
        public void succeed(String msg) {
            System.out.println(msg);
    
        }
    
        public void failed(String msg) {
            System.out.println(msg);
    
        }
    }

#### Server ####

public class Server {
    
        public void login(String userName,String password,LoginListener listener) {
            System.out.print("loading");
            for (int i = 0; i < 10; i++) {
                try {
                    Thread.sleep(100*i);
                    System.out.print(".");
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if(userName.equals("zhangsan") && password.equals("123")){
                if(listener!=null){
                    listener.succeed("登录成功");
                }
            }else{
                if(listener!=null){
                    listener.succeed("登录失败");
                }
            }
    
        }
    }

测试类

public class LoginTest {
    
        public static void main(String[] args) {
            Scanner sc = new Scanner(System.in);
            System.out.println("请输入用户名：");
            String userName = sc.next();
            System.out.println("请输入用户密码：");
            String password = sc.next();
    
            Server server = new Server();
            server.login(userName, password, new MyLoginListener());
    
        }
    }

*  输出结果

> 请输入用户名：  
> zhangsan  
> 请输入用户密码：  
> 123  
> loading……….登录成功