JSP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 lmq; //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(Super)，1个有参(Fields) public class Book { int id; String name; double price; public int getId() { return id; } public void setId(int 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(int id, String name, double price) { super(); this.id = id; this.name = name; this.price = price; } public Book() { super(); // TODO Auto-generated constructor stub } @Override public String toString() { return "Book ["id=" + id + ", name=" + name + ", price=" + price + "]"; } }
package lmq; //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 import java.util.ArrayList; import java.util.List; import java.util.Scanner; public class Main { static java.util.List<Book> list = new ArrayList<Book>(); static {//static是静态修饰符,修饰的成员可以通过类名加'.'进直接访问 Book b1 = new Book(1, "book1", 11.11); Book b2 = new Book(2, "book2", 22.22); Book b3 = new Book(3, "book3", 33.33); list.add(b1); list.add(b2); list.add(b3); } /** * @param args * @return */ public static void main(String[] args) { // TODO Auto-generated method stub while (true) { System.out.println("主页面"); 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.退出程序"); System.out.println("请选择1-5"); 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 5: 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"); double c1 = new Scanner(System.in).nextDouble(); 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 //构造一个Scanner类的对象来获取用户的输入 Scanner scanner = new Scanner(System.in); System.err.println("请输入id"); int id = scanner.nextInt(); System.err.println("请输入名称"); String name = scanner.next(); System.err.println("请输入价格"); double price = scanner.nextDouble(); Book book = new Book(id, name, price); 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="lmq.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> <head> </head> <body> <% List<Book> list=new ArrayList<Book>(); Book b1 = new Book(1, "book1", 11.11); Book b2 = new Book(2, "book2", 22.22); Book b3 = new Book(3, "book3", 33.33); list.add(b1); list.add(b2); list.add(b3); for(Book book4:list){ out.println(book4+"<br>"); } %> </body> </html>
3.在MySQL中创建Book表，里面id,name,price,用命令实现
create database books; use books; create table book( id int(10), name varchar(10), price float );
添加一个图书，
insert into book values('1','我我我','9.99'); insert into book values('2','嗨害嗨','99.99');
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;
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;
