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

Book类
package r;

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();
    }
    

}
Main类
package r;

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, "万水千山走遍", 66.6);
        Book b2 = new Book(2, "温柔的夜", 77.7);
        Book b3 = new Book(3, "梦里花落知多少", 88.8);
        list.add(b1);
        list.add(b2);
        list.add(b3);
        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 language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@page import="r.Book"%>
<!DOCTYPE HTML >
<html>
<head>
<title>My JSP 'index.jsp' starting page</title>
</head>
<body>
    
    <%
        List<Book> list = new ArrayList<Book>();
        Book b1 = new Book(1, "雨季不再来", 66);
        Book b2 = new Book(2, "我的宝贝", 77);
        Book b3 = new Book(3, "送你一匹马", 88);
        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,添加一个图书,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,把20元以上的图书价格都修改为18.8,查看全部图书,查看价格高于10块钱的全部图书

create table book(
id int(10) auto_increment primary key,
name varchar(30),
price double(5,2));
insert into Book(id,name,price)values(1,"稻草人手记",999);
delete from book where name='亲爱的三毛';
 delete from book where name like '我%';
delete from book;
update book set price=18.8 where price>20;
select * from book;
select * from book where price>10;
posted on 2022-04-27 12:17  郝梦瑶  阅读(14)  评论(0编辑  收藏  举报