第九次作业
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
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 po; 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 po; 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, "三毛流浪记", 100); 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="po.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,
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','三毛,'33);
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;