【java】【基础6】面对对象

目录

一、面对对象快速入门 

二、深刻认识面对对象

三、对象在计算机中的执行原理

四、类和对象的一些注意事项

五、this

六、构造器

七、封装

八、实体javaBean

 8.1 演示自动生成get set方法

 8.2 自动生成构造器

 8.3 数据和业务相分离案例

九、面对对象变成综合案例

 9.1 设计一个movie实体类

9.2 设计MovieOperator操作类

9.3 TestMovie准备电影数据（main）

十、补充知识：成员变量和局部变量的区别

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前言：java是面对对象编程，本内容是入门开始

一、面对对象快速入门 

 

 

二、深刻认识面对对象

三、对象在计算机中的执行原理

   

四、类和对象的一些注意事项

五、this

 

 

 

六、构造器

构造器是一种特殊的方法，特殊在方法名与所在类名一样，而且不能写返回值类型

构造器可以是多个

  

七、封装

 

 

八、实体javaBean

 8.1 演示自动生成get set方法

1、原类

 2、右击

 

 3、选择

 

 4、可配合shift

 5、完成

 8.2 自动生成构造器

1、原类

 2、选择

 3、下图红色箭头表示选择有参数或者无参数的构造器

 4、结果

 8.3 数据和业务相分离案例

1、目录结构

2、代码Test、Student代码和StudentOperator代码 

 3、运行结果

 

 4、代码

Test

package com.runa.object;

public class Test {
    public static void main(String[] args) {
        Student s1 = new Student();
        s1.setName("春天的菠菜");
        s1.setScore(100);
        System.out.println(s1.getName());
        System.out.println(s1.getScore());

        StudentOperation operation = new StudentOperation(s1);
        operation.printPass();

        Student s2 = new Student("lisa",59);
        StudentOperation operation2 = new StudentOperation(s2);
        operation2.printPass();
    }
}

 Student

package com.runa.object;

public class Student {
    // 私有的成员变量，每个成员变量都提供set 和get方法
    private String name;
    private double score;

    // 无参数的构造方法
    public Student() {
    }

    // 有参数的构造方法
    public Student(String name, double score) {
        this.name = name;
        this.score = score;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public double getScore() {
        return score;
    }

    public void setScore(double score) {
        this.score = score;
    }
}

 StudentOperator

package com.runa.object;

public class StudentOperation {
    private Student student;
    //无参数的构造方法
    public StudentOperation() {
    }

    //有参数的构造方法
    public StudentOperation(Student student) {
        this.student = student;
    }
    //操作方法
    public void printPass(){
        if(student.getScore() >= 60){
            System.out.println(student.getName() +"学生成绩及格");
        }else{
            System.out.println(student.getName() +"学生成绩不及格");

        }
    }
}

九、面对对象变成综合案例

 9.1 设计一个movie实体类

package com.runa.object;

public class Movie {
    private int id;
    private String name;
    private double price;
    private double score;
    private String director;
    private String actor;
    private String info;

    public Movie() {
    }

    public Movie(int id, String name, double price, double score, String director, String actor, String info) {
        this.id = id;
        this.name = name;
        this.price = price;
        this.score = score;
        this.director = director;
        this.actor = actor;
        this.info = info;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public double getScore() {
        return score;
    }

    public void setScore(double score) {
        this.score = score;
    }

    public String getDirector() {
        return director;
    }

    public void setDirector(String director) {
        this.director = director;
    }

    public String getActor() {
        return actor;
    }

    public void setActor(String actor) {
        this.actor = actor;
    }

    public String getInfo() {
        return info;
    }

    public void setInfo(String info) {
        this.info = info;
    }
}

9.2 设计MovieOperator操作类

package com.runa.object;

public class MovieOperator {
    private Movie[] Movies;

    //无参数的构造方法
    public MovieOperator() {
    }

    //有参数的构造方法
    public MovieOperator(Movie[] movies) {
        this.Movies = movies;
    }
    /**
     1.展示系统全部电影信息 movies=[m1,m2,m3]
     */
    public void printAllMovies(){
        System.out.println("-------系统全部电影信息如下-----------");
        for (int i = 0; i < Movies.length; i++) {
            Movie m = Movies[i];
            System.out.println("编号：" + m.getId());
            System.out.println("名称：" + m.getName());
            System.out.println("价格：" + m.getPrice());
            System.out.println("----------------");
        }
    }

    /**
     2 根据电影编号查询出该电影的详细信息展示出来
     */
    public void searchMovieById(int id){
        for (int i = 0; i < Movies.length; i++) {
            Movie m = Movies[i];
            if(m.getId() == id){
                System.out.println("该电影详情如下：");
                System.out.println("编号：" + m.getId());
                System.out.println("名称：" + m.getName());
                System.out.println("价格：" + m.getPrice());
                System.out.println("得分：" + m.getScore());
                System.out.println("导演：" + m.getDirector());
                System.out.println("主演：" + m.getActor());
                System.out.println("其他：" + m.getInfo());
                System.out.println("----------------");
                return;
            }

        }
        System.out.println("对不起，没有该电影信息");
    }
}

9.3 TestMovie准备电影数据（main）

package com.runa.object;

import java.util.Scanner;

public class TestMovie {
    public static void main(String[] args) {
        Movie[] movies = new Movie[4];
        movies[0] = new Movie(1,"水门桥",38.9,9.8,"徐克","吴京","12万人想看");
        movies[1] = new Movie(2,"出拳吧",39,7.8,"唐晓白","田雨","3.5万人想看");
        movies[2] = new Movie(3,"月球陨落",42,7.9,"罗兰","贝瑞","17.9万人想看");
        movies[3] = new Movie(4,"一点就到家",35,8.7,"许宏宇","刘昊然","10.8万人想看");
//        Movie m1 = new Movie(1,"水门桥",38.9,9.8,"徐克","吴京","12万人想看");
//        Movie m2 = new Movie(2,"出拳吧",39,7.8,"唐晓白","田雨","3.5万人想看");
//        Movie m3 = new Movie(3,"月球陨落",42,7.9,"罗兰","贝瑞","17.9万人想看");
//        Movie m4 = new Movie(4,"一点就到家",35,8.7,"许宏宇","刘昊然","10.8万人想看");
//        movies[0] = m1;
//        movies[1] = m2;
//        movies[2] = m3;
//        movies[3] = m4;

        // 创建电影操作类对象,接收电影数据，操作业务
//        MovieOperator operator = new MovieOperator(movies);
//        operator.printAllMovies();
//        operator.searchMovieById(1);
        MovieOperator operator = new MovieOperator(movies);
        Scanner sc = new Scanner(System.in);
        while (true) {
            System.out.println("==电影信息系统==");
            System.out.println("1、 查询全部电影作品");
            System.out.println("2、 根据电影id查询某个电影的详细信息展示");
            System.out.println("请你输入操作命令");
           
            int command = sc.nextInt();
            switch (command){
                case 1:
                    //展示全部电影信息
                    operator.printAllMovies();
                    break;

                case 2:
                    //根据id查询某个电影的全部信息
                    System.out.println("请您输入查询的电影id");
                    int id = sc.nextInt();
                    operator.searchMovieById(id);
                    break;
                default:
                    System.out.println("**************************************");
                    System.out.println("********您输入的命令有问题！**************");
                    System.out.println("**************************************");
            }
        }


    }
}

十、补充知识：成员变量和局部变量的区别