java实现简单的图书管理系统简单框架（便于理解）

框架意义：

理解menu菜单的选择与返回上一级的实现

不确定循环次数用while对应不确定输入错误的次数

如何退出一层循环，break

如何保证只有一个出口，合理利用while1与break,switch,if。 

package com.w3day3.test1.model;

/**
 * @Title
 * @Author Eastlin
 * @Description:
 */
public abstract class Person {
    public String pname;//用户名等等
    private   String sex;
    private int age;
    public static Book[] books = new Book[]{
            new Book("西游记", "吴承恩", 10, "名著", true),
            new Book("红楼梦", "曹雪芹", 20, "名著", true),
            new Book("三国演义", "罗贯中", 15, "名著", true),
            new Book("小茗同学", "小明", 5, "杂志", true),
            new Book("C与指针", "马老师", 35, "计算机", true),
            new Book("Java编程思想", "王老师", 55, "计算机", true),
            new Book("新世界", "陈宇", 15, "杂志", true),
            new Book("阿衰与大头妹", "阿衰", 5, "漫画", true),
            new Book("一个人就一个人", "刘同", 35, "小说", true),
            new Book("活着", "陈彤", 36, "小说", true),
            new Book(),
            new Book(),
            new Book(),
    };

    public Person() {
    }

    public Person(String pname, String sex, int age) {
        this.pname = pname;
        this.sex = sex;
        this.age = age;
    }

    @Override
    public String toString() {
        return "当前普通用户：姓名："+ this.pname+ " "+"性别：" +this.sex+ " "+"年龄："+this.age;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
    public  abstract void operate(int i);
}





package com.w3day3.test1.model;

/**
 * @Title
 * @Author Eastlin
 * @Description:
 */
public class Book {
    private String bookName;
    private String authorName;
    private double price;
    private  String type;
    private boolean status;//标志位，用于逻辑删除（可以减少字段的增删）

    public Book(String bookName, String authorName, double price, String type, boolean status) {
        this.bookName = bookName;
        this.authorName = authorName;
        this.price = price;
        this.type = type;
        this.status = status;
    }
    public Book() {  //默认10本书
        this(10);
    }
    public Book(int i) {
        Person.books = new Book[i];//Person类变量
    }
    @Override
    public String toString() {//重写输出对象
        return "【" + bookName+ "】—— 【" + authorName + "】——【" + price + "】——【" +type+ "】——" +status;
    }
    public String getBookName() {
        return bookName;
    }

    public void setBookName(String bookName) {
        this.bookName = bookName;
    }

    public String getAuthorName() {
        return authorName;
    }

    public void setAuthorName(String authorName) {
        this.authorName = authorName;
    }

    public double getPrice() {
        return price;
    }

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

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    public boolean isStatus() {
        return status;
    }

    public void setStatus(boolean status) {
        this.status = status;
    }

}



package com.w3day3.test1.model;

import com.w3day3.test1.Root;
import com.w3day3.test1.User;

import java.util.Scanner;

/**
 * @Title
 * @Author Eastlin
 * @Description:
 */
public class Library {
    //在这我们也可以加普通用户集合，管理员集合进行增删改查 TODO
    static User admin=new User("狂徒张三","男",35);//设置一个管理员
    Scanner input = new Scanner(System.in);
    //登录函数：显示主页
    public void login() {
        int count = 0;
        Person p = null;
        while (count < 2) {//死循环，搭配break
            System.out.println("===============Eastlin图书管理系统===============");
            System.out.println("欢迎讨论指正！ qq113397025" + "\n");
            System.out.println("请登录：1.普通用户  2.管理员登录  3.退出系统");

            System.out.print("输入数字进行选择：");
            int n =input.nextInt();
            //通过输入的值进行选择（代码是提供判断选择）
            if (n == 3) {//退出，结束代码运行
                return;
            }
            switch (n) {
                case 1://普通用户
                    System.out.println("请输入姓名：");
                    String name = input.next();
                    System.out.println("请输入性别：");
                    String sex = input.next();
                    System.out.println("请输入年龄：");
                    int age = input.nextInt();
                    p=new User(name,sex,age) ;

                    System.out.println("登录成功");
                    System.out.println(p);//显示当前用户，重写了toString
                    //普通用户循环操作
                    while (true) {//死循环，搭配break
                        System.out.println("请输入你的操作： 1.查询书籍 2.借阅书籍 3.归还书籍 4.显示书籍列表 5.退出");
                        int i = input.nextInt();
                        if (i == 5) {
                            System.out.println("您已成功退出！");
                            break;
                        }else {
                            p.operate(i);  //调用普通用户的操作方法(非选择数字5或其他，找不到方法停留在此死循环)
                            //不在范围，可if判断，输出提示  TODO
                        }
                    }
                    break;
                case 2:
                    System.out.println("请输入管理员姓名：");
                    String Rname = input.next();
                    System.out.println("请输入性别：");
                    String Rsex = input.next();
                    System.out.println("请输入年龄：");
                    int Rage = input.nextInt();

                    p = new Root(Rname,Rsex,Rage);//构造管理员对象
//进行管理员登录判断 TODO
                    System.out.println("登录成功！");
                    System.out.println(p);
                    while (true) {
                        System.out.println("请输入你的操作： 0.整理书籍 1.查阅书籍 2.增加书籍 3.删除书籍 4.显示书籍列表 5.退出");
                        int j = input.nextInt();
                        if (j == 5) {
                            System.out.println("您已成功退出！");
                            break;
                        }else{
                            p.operate(j);//调用管理员的操作方法
                            //不在范围，可if判断，输出提示  TODO
                        }
                    } break;

            }

        }
    }
}


package com.w3day3.test1;

import com.w3day3.test1.model.Person;
//Root仅仅比User多一个整理的方法,看着可以尝试优化，
// 但是会显得程序复杂，一个是+操作，一个是-操作。是相似，不是相同

/**
 * @Title
 * @Author Eastlin
 * @Description:
 *管理员操作选择
 * 用户操作+整理（有序才便于查找）
 */
public class Root extends Person implements Operate {
    public Root() {
    }

    public Root(String pname, String sex, int age) {
        super(pname, sex, age);
    }

    @Override
    public void operate(int i) {//操作选择（判断实现）TODO
        System.out.println(0+"你选择了"+i);
        switch (i){
            case 0:
                sort();//整理书籍
                break;
            case 1:
                findBook();//找书
                break;
            case 2:
                deleteBook();//删书
                break;
            case 3:
                addBook();//加书
                break;
            case 4:
                showBook();//书籍列表
                break;
        }
    }
    public void sort(){//整理，管理员特有
        System.out.println(00);
    }

    @Override
    public void findBook() {
        System.out.println(01);
    }

    @Override
    public void deleteBook() {
        System.out.println(02);
    }

    @Override
    public void addBook() {
        System.out.println(03);
    }

    @Override
    public void showBook() {
        System.out.println(04);
    }
}


package com.w3day3.test1;

import com.w3day3.test1.model.Person;


/**
 * @Title
 * @Author Eastlin
 * @Description:
 */
public class User extends Person implements Operate {
    public User() {
    }

    public User(String pname, String sex, int age) {
        super(pname, sex, age);
    }

    @Override
    public void operate(int i) {//操作选择（判断实现）TODO
        System.out.println(0+"你选择了"+i);
        switch (i){
            case 1:
                findBook();//找书
                break;
            case 2:
                deleteBook();//借书
                break;
            case 3:
                addBook();//还书
                break;
            case 4:
                showBook();//书籍列表
                break;
        }
    }

    @Override
    public void findBook() {
        System.out.println(01);
    }

    @Override
    public void deleteBook() {
        System.out.println(02);
    }

    @Override
    public void addBook() {
        System.out.println(03);
    }

    @Override
    public void showBook() {
        System.out.println(04);
    }
}

package com.w3day3.test1;

/**
 * @Title
 * @Author Eastlin
 * @Description:
 */
public interface Operate {
    public void findBook();//1.查询、查阅
    public void deleteBook();//2.删除、借阅
    public void addBook();//3.增加、还书
    public void showBook();//4.显示书籍列表
}

package com.w3day3.test1;

import com.w3day3.test1.model.Library;

/**
 * @Title
 * @Author Eastlin
 * @Description:
 */
public class Main {
    public static void main(String[] args) {
        Library library=new Library();
        library.login();
    }
}