1.book类

package book;

/**
 * 实体类（领域模型） 特点：只有属性，没有方法。因为他的目的就是承载数据。
 */
public class Book {

    private int bookId;
    private String bookName;
    private String bookAuthor;
    private double bookPrice;
    private String content;

    public Book() {
    }

    public Book(int bookId, String bookName, String bookAuthor, double bookPrice, String content) {
        this.bookId = bookId;
        this.bookName = bookName;
        this.bookAuthor = bookAuthor;
        this.bookPrice = bookPrice;
        this.content = content;
    }

    @Override
    public String toString() {
        return this.bookId + "\t" + this.bookName + "\t" + this.bookAuthor + "\t" + this.bookPrice + "\t"
                + this.content;
    }

    public int getBookId() {
        return bookId;
    }

    public void setBookId(int bookId) {
        this.bookId = bookId;
    }

    public String getBookName() {
        return bookName;
    }

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

    public String getBookAuthor() {
        return bookAuthor;
    }

    public void setBookAuthor(String bookAuthor) {
        this.bookAuthor = bookAuthor;
    }

    public double getBookPrice() {
        return bookPrice;
    }

    public void setBookPrice(double bookPrice) {
        this.bookPrice = bookPrice;
    }

    public String getContent() {
        return content;
    }

    public void setContent(String content) {
        this.content = content;
    }
}

2.测试类

package book;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Test {

    public void work() {
        Scanner input = new Scanner(System.in);

        Book sanguo = new Book(1, "三国演义", "罗贯中", 40.5, "三国演义好看！");
        Book shuihu = new Book(2, "水浒", "施耐庵", 45, "水浒好看！");
        Book xiyouji = new Book(3, "西游记", "吴承恩", 50.5, "西游记好看！");
        Book hongloumeng = new Book(4, "红楼梦", "曹雪芹", 30, "红楼梦好看！");

        List<Book> list = new ArrayList<>();
        list.add(sanguo);
        list.add(shuihu);
        list.add(xiyouji);
        list.add(hongloumeng);

        System.out.println("--------------------欢迎使用图书管理系统----------------------\n");

        int menu = 0;
        while (menu != 5) {
            System.out.println("---- 主菜单--1.全查询--2.添加--3.更新--4.删除--5.退出----");
            System.out.println("请选择主菜单功能：");
            menu = input.nextInt();
            switch (menu) {
                case 1:
                    showListBook(list);    //全查询
                    break;
                case 2:
                    saveBook(list);
                    break;
                case 3:
                    updateBook(list);
                    break;
                case 4:
                    removeBook(list);
                    break;
                case 5:
                    System.out.println("-----------------------欢迎下次光临----------------------");
                    break;
                default:
                    System.out.println("请输入正确的选项！");
                    break;
            }
        }
    }
    
    private void showListBook(List<Book> list) {
        System.out.println("\n书籍编号\t书籍名称\t书籍作者\t书籍价格\t书籍简介");
        for(Book book : list) {
            System.out.println(book);
        }
    }
    
    private void saveBook(List<Book> list) {
        Scanner input = new Scanner(System.in);
        
        //查找最大书籍编号
        int maxBookId = 0;
        for(Book book : list) {
            if(maxBookId<book.getBookId()) {
                maxBookId = book.getBookId();
            }
        }
        
        Book book = new Book();
        
        book.setBookId(maxBookId+1);
        
        System.out.println("请输入书籍名称：");
        book.setBookName(input.next());
        System.out.println("请输入书籍作者：");
        book.setBookAuthor(input.next());
        System.out.println("请输入书籍价格：");
        book.setBookPrice(input.nextDouble());
        System.out.println("请输入书籍简介：");
        book.setContent(input.next());
        
        list.add(book);
        System.out.println("添加成功！");
    }
    
    private void updateBook(List<Book> list) {
        Scanner input = new Scanner(System.in);
        
        showListBook(list);
        
        System.out.println("请输入要更新的书籍编号：");
        int bookId = input.nextInt();
        for(Book book : list) {
            if(book.getBookId()==bookId) {
                System.out.println("\n书籍编号\t书籍名称\t书籍作者\t书籍价格\t书籍简介");
                System.out.println(book);
                
                System.out.println("书籍名称是否修改(y/n)：");
                if(input.next().equals("y")) {
                    System.out.println("请输入新的书籍名称：");
                    book.setBookName(input.next());
                }
                
                System.out.println("书籍作者是否修改(y/n)：");
                if(input.next().equals("y")) {
                    System.out.println("请输入新的书籍作者：");
                    book.setBookAuthor(input.next());
                }
                
                System.out.println("书籍价格是否修改(y/n)：");
                if(input.next().equals("y")) {
                    System.out.println("请输入新的书籍价格：");
                    book.setBookPrice(input.nextDouble());
                }
                
                System.out.println("书籍简介是否修改(y/n)：");
                if(input.next().equals("y")) {
                    System.out.println("请输入新的书籍简介：");
                    book.setContent(input.next());
                }
                
                System.out.println("修改成功！");
                break;
            }
        }
    }
    
    private void removeBook(List<Book> list) {
        Scanner input = new Scanner(System.in);
        showListBook(list);
        System.out.println("请输入要删除的书籍编号：");
        int bookId = input.nextInt();
        Book temp = null;
        for(Book book : list) {
            if(book.getBookId()==bookId) {
                temp = book;
                break;
            }
        }
        list.remove(temp);
        System.out.println("删除成功！");
    }

    public static void main(String[] args) {
        new Test().work();
    }

}