第九次

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.nn.com;

public class Book {
    private Integer id;
    private String name;
    private Integer 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 Integer getPrice() {
        return price;
    }
    public void setPrice(Integer price) {
        this.price = price;
    }
    public Book(Integer id, String name, Integer price) {
        super();
        this.id = id;
        this.name = name;
        this.price = price;
    }
    public Book() {
        super();
    }
    @Override
    public String toString() {
        return "Book [id=" + id + ", name=" + name + ", price=" + price + "]";
    }
    
}

 

package com.nn.com;

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

import jdk.nashorn.internal.runtime.regexp.joni.SearchAlgorithm;

import sun.applet.Main;

public class Run {
    static java.util.List<Book> list =new ArrayList<Book>();
    static{
        Book book1 =new Book(1, "西游记", 10);
        Book book2 =new Book(2, "水浒传", 20);
        Book book3 =new Book(3, "三国演义", 30);
        list.add(book1);
        list.add(book2);
        list.add(book3);
    }
    /**
     * @param args
     * @return 
     */
    
        
    
public static void main(String[] args) {
        // TODO Auto-generated method stub
        while(true){
            System.out.println("1.添加");
            System.out.println("2.删除");
            System.out.println("3.修改");
            System.out.println("4.查询");
            System.out.println("0.退出程序");
        System.out.println("请选择0-4");
        Scanner scanner=new Scanner(System.in);
        int i=scanner.nextInt();
        switch (i) {
        case 1:
            addbook();
            System.out.println("是否返回主界面Y/N?");
            String s=scanner.next();
            if (s.equals("Y")) {
                break;
            }
            else {
                return;
            }
        case 2:
            delBoook();
            System.out.println("是否返回主界面Y/N?");
            s=scanner.next();
            if (s.equals("Y")) {
                break;
            }
            else {
                return;
            }
        case 3:
            update();
            System.out.println("是否返回主界面Y/N?");
            s=scanner.next();
            if (s.equals("Y")) {
                break;
            }
            else {
                return;
            }
        case 4:
            search();    
            System.out.println("是否返回主界面Y/N?");
            s=scanner.next();
            if (s.equals("Y")) {
                break;
            }
            else {
                return;
            }
        case 0:
            System.out.println("退出成功");
            return;
        }
        
    }
}
    private static void search() {
        // TODO Auto-generated method stub
        for (Book book4 : list) {
            System.out.println(book4);
        }
    }
    private static void update() {
        // TODO Auto-generated method stub
        System.out.println("请输入修改的图书id");
        int update=new Scanner(System.in).nextInt();
        
        for (Book book : list) {
            if (update==book.getId()) {
                System.err.println("请输入名称");
                String b1=new Scanner(System.in).next();
                System.err.println("请输入价格");
                int c1=new Scanner(System.in).nextInt();
                book.setName(b1);
                book.setPrice(c1);
                System.out.println("修改成功");
            }
        }
       
    }
    private static void delBoook() {
        System.out.println("请输入你要删除的图书id");
        int id=new Scanner(System.in).nextInt();
        try {
            for (Book book : list) {
                if (list.size()!=0) {
                    if (id==book.getId()) {
                        list.remove(book);
                        System.out.println("删除成功");
                    }
                }
            }
        } catch (Exception e) {
            // TODO: handle exception
        }
        
    }
    private static void addbook() {
        // TODO Auto-generated method stub
        
        Scanner scanner=new Scanner(System.in);
        System.err.println("请输入id");
        int a=scanner.nextInt();
        System.err.println("请输入名称");
        String b=scanner.next();
        System.err.println("请输入价格");
        int c=scanner.nextInt();
        
        Book book=new Book(a, b, c);
        list.add(book);
        System.out.println("添加成功");
        
        
    }
    
    
}

 

 


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.nn.com.Book"%>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
 <%List<Book> list =new ArrayList<Book>();
   Book book1 =new Book(1,"java",10);
   list.add(book1);
    Book book2 =new Book(2,"web",20);
   list.add(book2);
    Book book3 =new Book(3,"html",30);
   list.add(book3);
 	for (Book book4 : list) {
			out.print(book4+"<br>");
	}
  %>
  <body>
  </body>
</html>

  

 

 


3.在MySQL中创建Book表,里面id,name,price

create database books;
use books;

create table book(
id int(10),
name varchar(10),
price float
);

 

 

用命令实现,
添加一个图书,

 insert into book values('1','我的世界','22.5');

  

 

 


根据名称删除图书,
把所有名称是“我”开头的图书删除,

delete from book where name like '我%';

  

 

 


删除全部图书,

delete   from book;

  

 

 


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;

  

 

 


查看全部图书,

 select * from book;

  

 

 


查看价格高于10块钱的全部图书

 select * from book where price >10;

  

 

 

posted @ 2022-04-27 12:58  倪楠  阅读(50)  评论(0编辑  收藏  举报