JAVA图书管理练习

0.前言

  1.在学习了面向对象,接口继承等语法后,综合使用这些语法完成一个简单的图书管理小练习.

2.在写代码之前,我们首先要把各种类抽象出来,图书管理会有多个类,比如书类,放书的书架类,操作书籍的类,用户类

1.书类(BOOK)

1.1 Book

先创建一个包,里面存放书类和书架类,

BOOK类包含五个成员变量并且添加构造方法等其他成员方法,当我们实例化对象后,一本书就会有这五个属性和成员方法.

public class Book {
    private String name; //书名
    private String author; //作者
    private int price; //价格
    private String type; //类型
    private Boolean isBorrowed=false; //是否借出

    public String getName() {
        return name;
    }

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

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    public int getPrice() {
        return price;
    }

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

    public String getType() {
        return type;
    }

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

    public Boolean getBorrowed() {
        return isBorrowed;
    }

    public void setBorrowed(Boolean borrowed) {
        isBorrowed = borrowed;
    }

    @Override
    public String toString() {
        return "Book{" +
                "name='" + name + '\'' +
                ", author='" + author + '\'' +
                ", price=" + price +
                ", type='" + type + '\'' +
                ", isBorrowed=" + (isBorrowed?"true":"false")  +
                '}';
    }

    public Book(String name, String author, int price, String type) {
        this.name = name;
        this.author = author;
        this.price = price;
        this.type = type;
    }

}

1.2 BookList

书架用来存放实例化后的书对象,里面包含了两个成员变量,一个是记录存放书籍数量的UsedSize,另外一个是创建的Book类数组,用来存放书对象.

   //BookList

    Book[] books=new Book[10];
    
    int UsedSize; //已借出书籍的数量

public class BookList {
    private Book[] books=new Book[10];
    private int UsedSize; //已借出书籍的数量

    public  BookList(){
        this.books[0]=new Book("三国演义","罗贯中",119,"小说");
        this.books[1]=new Book("鸟哥的 Linux 私房菜","鸟哥",118,"小说");
        this.books[2]=new Book("剑指 Offer","何海涛",65,"小说");
        this.UsedSize=3;
    }
    //放书
    public void setBooks(int pos,Book book) {
        books[pos]=book;
    }

    public int getUsedSize() {
        return UsedSize;
    }

    public void setUsedSize(int UsedSize) {
        this.UsedSize = UsedSize;
    }

    public Book getbook(int pos){
        return books[pos];
    }
}

2. User类

2.1 user类

我们把用户分为管理员和普通用户,分别对应不同的功能

User类

public  abstract class User {
    protected String name;
    public abstract int menu();

    protected Ioperation[] ioperations;

    public User(String name) {
        this.name = name;
    }

    public void dowork(int choice, BookList bookList){
        this.ioperations[choice].work(bookList);
    }

}

2.2 AdminUser类

public class AdminUser extends User {
    public AdminUser(String name) {
        super(name);
        this.ioperations =new Ioperation[]{
                new ExitOperation(),
                new AddOperation(),
                new FindOperation(),
                new DisplayOperation(),
                new DelOperation()
        };
    }

    public int menu() {
        System.out.println("=============================");
        System.out.println("Hello " + name + ", 欢迎使用图书管理系统!");
        System.out.println("0. 退出系统");
        System.out.println("1. 增加图书");
        System.out.println("2. 查找图书");
        System.out.println("3. 展示图书");
        System.out.println("4. 删除图书");
        System.out.println("=============================");
        System.out.println("请输入要选择的选项:");
        Scanner sc = new Scanner(System.in);
        int choice = sc.nextInt();
        return choice;
    }
}

2.3 NormalUser类

public class NormUser extends User{
    public int menu() {
        System.out.println("=============================");
        System.out.println("Hello " + name + ", 欢迎使用图书管理系统!");
        System.out.println("0. 退出系统");
        System.out.println("1. 展示图书");
        System.out.println("2. 查找图书");
        System.out.println("3. 借阅图书");
        System.out.println("4. 归还图书");
        System.out.println("=============================");
        System.out.println("请输入要选择的选项:");
        Scanner sc = new Scanner(System.in);
        int choice = sc.nextInt();
        return choice;
    }
    public NormUser(String name){
        super(name);
        this.ioperations=new Ioperation[]{
                new ExitOperation(),
                new DisplayOperation(),
                new FindOperation(),
                new BorrowOperation(),
                new ReturnOperation()
        };
    }
}
`

3.Operation类

public interface Ioperation {
    void work(BookList bookList);
}

3.1 添加图书

public class AddOperation implements Ioperation {
    public void work(BookList bookList){
        System.out.println("添加图书");
        Scanner sc=new Scanner(System.in);
        System.out.println("请输入书名:");
        String name=sc.nextLine();
        System.out.println("请输入作者:");
        String author=sc.nextLine();
        System.out.println("请输入价格:");
        int price=sc.nextInt();
        System.out.println("请输入书的类型:");
        
        String type=sc.nextLine();
        Book book=new Book(name,author,price,type);
        int pos= bookList.getUsedSize();
        
        bookList.setBooks(pos,book);
        bookList.setUsedSize(pos+1);
        System.out.println("图书添加完成");
    }
}

3.2 删除图书

public class DelOperation implements Ioperation{
    @Override
    public void work(BookList booklist) {
        System.out.println("删除图书");
        Scanner sc=new Scanner(System.in);
        System.out.println("请输入要删除的图书:");
        String name=sc.nextLine();
        for (int i = 0; i < booklist.getUsedSize(); i++) {
            if(name.equals(booklist.getbook(i).getName())){
                while(booklist.getUsedSize()-i-1!=0){
                    booklist.setBooks(i,booklist.getbook(i+1));
                    i++;
                }
                booklist.setUsedSize(booklist.getUsedSize()-1);
                System.out.println("删除成功");
                return;
            }
        }
        System.out.println("删除失败,没有这本书");
    }
}

3.3 查找图书

public class FindOperation implements Ioperation{
    @Override
    public void work(BookList booklist) {
        System.out.println("查找图书");
        System.out.println("请输入要查找的图书:");
        Scanner sc=new Scanner(System.in);
        String name=sc.nextLine();
        for (int i = 0; i < booklist.getUsedSize(); i++) {
            Book book=booklist.getbook(i);
            if(book.getName().equals(name)){
                System.out.println("找到了");
                System.out.println(book);
                return;
            }
        }
        System.out.println("没有找到");
    }

}

3.4 展示图书

public class DisplayOperation implements Ioperation {
    @Override
    public void work(BookList booklist) {
        System.out.println("展示图书");
        for (int i = 0; i < booklist.getUsedSize(); i++) {
            Book book=booklist.getbook(i);
            System.out.println(book);
        }
    }
}

3.5 退出系统

public class ExitOperation implements Ioperation {
    @Override
    public void work(BookList booklist) {
        System.out.println("退出系统");
        System.exit(0);
    }
}

3.6 借阅图书

public class BorrowOperation implements Ioperation {
    @Override
    public void work(BookList booklist) {
        System.out.println("借阅图书");
        System.out.println("请输入要借阅的图书:");
        Scanner sc=new Scanner(System.in);
        String name=sc.nextLine();
        int i;
        for(i = 0; i < booklist.getUsedSize(); i++) {
            Book book=booklist.getbook(i);
            if(book.getName().equals(name) && !book.getBorrowed()){
                System.out.println("借阅成功");
                booklist.getbook(i).setBorrowed(true);
                return;
            }
            System.out.println("借阅失败,该书已经被借阅");
            return;
        }
        System.out.println("没有找到这本书");
    }

    }

3.7 归还图书

public class ReturnOperation implements Ioperation {
    @Override
    public void work(BookList bookList) {
        System.out.println("归还图书");
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入归还书籍的名称");
        String name = sc.next();
        for (int i = 0; i < bookList.getUsedSize(); i++) {
            if (name.equals(bookList.getbook(i).getName())) {
                if (bookList.getbook(i).getBorrowed()) {
                    System.out.println("归还成功");
                    bookList.getbook(i).setBorrowed(false);
                    return;
                } else {
                    System.out.println("该书未被借阅");
                    return;
                }
            }
        }
        System.out.println("没有该书或者书名错误");
    }
}