图书管理系统

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package com.company;

public class Book {
    public String name;
    public int state;
    public double date;
    public int count;

    public void print(int index) {
        System.out.println(index + "\t" + name + "\t\t" + state + "\t\t" + date + "\t" + count);
    }

    public void setBook(String mingzi, int zhuangtai, double riqi) {
        name = mingzi;
        state = zhuangtai;
        date = riqi;
    }
}

public class BookSet {

Book [] books = new Book[50];

}

public class BookManage {

BookSet bookSet = new BookSet();

public void initial() {
    Book jichujiaochen = new Book();
    jichujiaochen.setBook("java基础教程", 0, 2015 - 7 - 1);

    Book shuju = new Book();
    shuju.setBook("数据库技术", 1, 0);

    Book renyue = new Book();
    shuju.setBook("人月神话", 1, 0);

    bookSet.books[0] = jichujiaochen;
    bookSet.books[1] = shuju;
    bookSet.books[2] = renyue;
}

public void startMenu() {
    boolean flag = true;
    do {
        System.out.println("*********************");
        System.out.println("1 查看图书");
        System.out.println("2 新增图书");
        System.out.println("3 删除图书");
        System.out.println("4 借出图书");
        System.out.println("5 归还图书");
        System.out.println("6 退 出");
        System.out.println("*********************");
        Scanner scanner = new Scanner(System.in);
        System.out.println("请选择");

        int gongnengbianhao = scanner.nextInt();
        switch (gongnengbianhao) {
            case 1:
                System.out.println("查看图书信息");
                chakan();  //调用查看商品信息的方法
                break;
            case 2:
                System.out.println("新增图书信息");
                add();
                break;
            case 3:
                System.out.println("删除图书信息");
                delete();
                break;
            case 4:
                System.out.println("借出图书");
                break;
            case 5:
                System.out.println("归还图书");
                break;
            case 6:
                System.out.println("退出系统");
                exit();
                flag = false;
                break;
            default:
                System.out.println("你输入的有误");
                break;
        }
    } while (flag);
}
public void exit() {
    System.out.println("退出");
}
    System.out.println("输入你要卖出的商品名称:");
    Scanner scanner = new Scanner(System.in);
    String name = scanner.next();
    for (int i = 0; i < bookSet.books.length; i++){
        if(bookSet.books[i].name.equals(name)){
            System.out.println("输入卖出的数量");
            int shoumai = scanner.nextInt();
            if( shoumai < bookSet.books[i].state){
                bookSet.books[i].state = bookSet.books[i].state - shoumai;
                bookSet.books[i].state = bookSet.books[i].state + shoumai;
            }
            System.out.println("售卖成功");
            break;
        }
    }
}

//删除商品
public void delete(){
    System.out.println("亲输入你要删除的商品编号");
    Scanner scanner = new Scanner(System.in);
    int delNo = scanner.nextInt();
    for(int i = 0; i < bookSet.books.length;i++) {
        if (bookSet.books[i] != null && (i + 1) == delNo) {//数组中的元素存在&&找到要删除的元素i
            int j = i;
            while (bookSet.books[j + i] != null) {// 要移动的元素后一个位置不为空，不执行以下操作
                bookSet.books[j] = bookSet.books[j + i]; //把后面元素的值覆盖在前面的元素上
                j++;
            }
            bookSet.books[i] = null; // 最后一个元素手动修改为空
            System.out.println("删除成功！");
        }else {
            System.out.println("删除失败！");
        }
    }
}

// 查看
public void chakan() {
    System.out.println("编号:\t 名称 \t 状态 \t 日期");
    for (int i = 0; i < bookSet.books.length; i++) {
        if (bookSet.books[i] != null) {
            bookSet.books[i].print(i + 1);
        }
    }
}
// 添加
public void add() {
    System.out.println("请输入图书名称");
    Scanner scanner = new Scanner(System.in);
    String name = scanner.next();

    System.out.println("请输入状态");
    double zt = scanner.nextDouble();

    System.out.println("请输入日期");
    int riqi = scanner.nextInt();

    Book newBook = new Book();

    newBook.setBook(name, (int) zt, riqi);

    for (int i = 0; i < bookSet.books.length; i++) {
        if (bookSet.books[i] == null) {
            bookSet.books[i] = newBook;
            break;
        }


    }
}

}
public class Demo {

public static void main(String[] args) {
    BookManage bookManage = new BookManage();
    bookManage.initial();
    bookManage.startMenu();
}

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