9 

package ly;
/*
 * 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
 */

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

}
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package ly;
import java.util.List;
import java.util.ArrayList;
import java.util.Scanner;

public class test {
    static java.util.List<Book> list=new ArrayList<Book>();
    static{
        Book book1=new Book(1,"红楼梦",30);
        Book book2=new Book(2,"西游记",25);
        Book book3=new Book(3,"三国演义",31);
        list.add(book1);
        list.add(book2);
        list.add(book3);
    }
    
    
    
    
    public static void main(String[] args) {
        
    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("5.退出");
        System.out.println("请选择");
        Scanner scanner=new Scanner(System.in);
        int a=scanner.nextInt();
            switch (a) {
            case 1:
                add();        
                break;
            case 2:
                del();
                break;
            case 3:
                change();
                break;
            case 4:
                search();
                break;
            case 5:
                System.out.println("退出成功");
                return;
            }
    }
        }
    private static void search(){
        for(Book book4:list){
            System.out.println(book4);
        }
    }
    private static void change(){
        System.out.println("请输入需要修改的图书编号");
        int update=new Scanner(System.in).nextInt();
        for(Book book:list){
            if(update==book.getId()){
                System.err.println("请输入书名");
                String name1=new Scanner(System.in).next();
                System.err.println("请输入价格");
                int price1=new Scanner(System.in).nextInt();
                book.setName(name1);
                book.setPrice(price1);
                System.out.println("修改成功");
            }
        }
    }
    private static void del(){
        System.out.println("请输入删除的图书编号");
        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){
            
        }
    }
    private static void add(){
        Scanner scanner=new Scanner(System.in);
        System.err.println("请输入编号");
        int idd=scanner.nextInt();
        System.err.println("请输入书名");
        String name2=scanner.next();
        System.err.println("请输入价格");
        int price2=scanner.nextInt();
        Book book=new Book(idd,name2,price2);
        list.add(book);
        System.out.println("添加成功");
    }

}
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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。

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<%@page import="ly.Book" %>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html>
  <%
  List<Book> list =new ArrayList<Book>();
   Book book1 =new Book(1,"红楼梦",30);
   list.add(book1);
    Book book2 =new Book(2,"西游记",25);
   list.add(book2);
    Book book3 =new Book(3,"三国演义",31);
   list.add(book3);
    for (Book book4 : list) {
            out.print(book4+"<br>");
    }
  %>
  <body>
  </body>
</html>
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3.在MySQL中创建Book表，里面id,name,price,

create table book(
id int(10) auto_increment primary key,
name varchar(30),
price double(5,2));

用命令实现，
添加一个图书，

insert into Book(id,name,price)values(1,"java",88);

根据名称删除图书，

delete from book where name='红楼梦';

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 @ 2022-05-08 12:12  张思文04  阅读(46)  评论(0)    收藏  举报