第九周作业

1.做一个图书类Book id,name,price ,get,set访问器，构造方法2个，1个无参，1个有参做一个测试类，在main中创建3个图书对象，放到list集合中。做一个菜单，可以添加，删除，修改，查询

package com.sjw;

public class Book {
    private Integer id;
    private String name;
    private double price;
    public Integer getId() {
        return id;
    }
    public void setId(Integer 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 Book(Integer id, String name, double price) {
        super();
        this.id = id;
        this.name = name;
        this.price = price;
    }
    public Book() {
        super();
    }

}

package com.sjw;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        List<Book> list = new ArrayList<Book>();
        Book book = new Book();
        Book b1 = new Book(1, "数据库", 99);
        Book b2 = new Book(2, "网络安全", 99);
        Book b3 = new Book(3, "微机原理", 99);
        Book b4 = new Book(4, "软件测试", 99);
        list.add(b1);
        list.add(b2);
        list.add(b3);
        list.add(b4);
        show(list, book);
    }

    public static void show(List<Book> list, Book book) {
        System.out.println("1.添加图书");
        System.out.println("2.删除图书");
        System.out.println("3.修改图书");
        System.out.println("4.查询图书");
        System.out.println("请选择");
        select(list, book);
    }

    public static void select(List<Book> list, Book book) {
        int i = new Scanner(System.in).nextInt();
        switch (i) {
            case 1:
                System.out.println("请添加图书的编号：");
                book.setId(new Scanner(System.in).nextInt());
                System.out.println("请添加图书的名称：");
                book.setName(new Scanner(System.in).next());
                System.out.println("请添加图书的价格：");
                book.setPrice(new Scanner(System.in).nextDouble());
                list.add(book);
                System.out.println("添加成功");
                show(list, book);

                break;
            case 2:
                System.out.println("请输入要删除图书的名称：");
                String name=new Scanner(System.in).next();
                for (int j = 0; list != null && j < list.size(); j++) {
                    if (list.get(j).getName().equals(name)) {
                        list.remove(j);
                    }
                }
                System.out.println("删除成功");
                show(list, book);
                break;
            case 3:
                System.out.println("请输入要修改图书的编号：");
                int k=new Scanner(System.in).nextInt();;
                for (int j = 0; list != null && j < list.size(); j++) {
                    if (list.get(j).getId().equals(k)) {
                        list.remove(j);
                        System.out.println("请输入修改后图书的名称：");
                        String name1=new Scanner(System.in).next();
                        System.out.println("请输入修改后图书的价格：");
                        double price1=new Scanner(System.in).nextDouble();
                        Book b=new Book(k,name1,price1);
                        list.add(b);
                        break;
                    }
                }
                System.out.println("修改成功");
                show(list, book);
                break;

            case 4:
                for (int j = 0; list != null && j < list.size(); j++) {
                    System.out.println(list.get(j).getId() + "."
                            + list.get(j).getName() + "," + list.get(j).getPrice());
                }
                show(list, book);
                break;
        }
    }
}

 

 

 

2.上题的类，在一个JSP页面中，创建一个集合，里面放3个图书，集合循环遍历显示在页面上。

<%@ page import="com.sjw.Book" %>
<%@ page import="java.util.List" %>
<%@ page import="java.util.ArrayList" %><%--
  Created by IntelliJ IDEA.
  User: 11512
  Date: 2022/5/1
  Time: 13:55
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>work</title>
</head>
<body>
<%
    List<Book> list = new ArrayList<Book>();
    Book b1 = new Book(1, "网络安全", 100);
    Book b2 = new Book(2, "微机原理", 80);
    Book b3 = new Book(3, "软件测试", 99.99);
    list.add(b1);
    list.add(b2);
    list.add(b3);
    for (int i = 0; list != null && i < list.size(); i++) {
        out.print(list.get(i).getId() + "." + list.get(i).getName()
                + "," + list.get(i).getPrice()+"<br>");
    }
%>
</body>
</html>

 

 

 

3.在MySQL中创建Book表，里面id,name,price,
用命令实现，

CREATE TABLE `book`  (
  `id` int(11) NOT NULL,
  `name` varchar(255),
  `price` double(10),
)

添加一个图书，

insert into book values(1,'JSP',50)

根据名称删除图书，

把所有名称是“我”开头的图书删除，

删除全部图书，

delete from book where name like '我%';

把20元以上的图书价格都修改为18.8，

update book set price = 18.8 where price > 20
select * from book

查看全部图书，
查看价格高于10块钱的全部图书

select * from book where price > 10
delete from book where name = 'JSP'