JSP第9次作业
package com.lrp.entity; 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, "数学", 88.8); Book b2 = new Book(2, "语文", 68.88); Book b3 = new Book(3, "生物", 99.9); 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"); System.out.println("2.删除"); System.out.println("3.修改"); System.out.println("4.查询"); 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("添加编号："); book.setId(new Scanner(System.in).nextInt()); System.out.println("添加名称："); book.setName(new Scanner(System.in).next()); System.out.println("添加价格："); book.setPrice(new Scanner(System.in).nextDouble()); list.add(book); System.out.println("完成"); show(list, book); break; case 2: System.out.println("要删除的名称："); 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("完成"); show(list, book); break; case 3: System.out.println("要修改的编号："); 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("修改后的名称："); String name1=new Scanner(System.in).next(); System.out.println("修改后的价格："); double price1=new Scanner(System.in).nextDouble(); Book b=new Book(k,name1,price1); list.add(b); break; } } System.out.println("完成"); 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; } } }
package com.lrp.entity; 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(); } }
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <%@page import="com.lrp.entity.Book"%> <!DOCTYPE HTML > <html> <head> <title>My JSP 'index.jsp' starting page</title> </head> <body> <!-- 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。 --> <% List<Book> list = new ArrayList<Book>(); Book b1 = new Book(1, "数学", 100); Book b2 = new Book(2, "语文", 80); Book b3 = new Book(3, "生物", 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,
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='js';
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;
