第七次作业
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。
package happy; /* * 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() { super(); // TODO Auto-generated constructor stub } public Book(Integer id, String name, Integer price) { super(); this.id = id; this.name = name; this.price = price; } @Override public String toString() { return "Book [id=" + id + ", name=" + name + ", 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; } } 复制代码 复制代码 package happy; import java.util.ArrayList; import java.util.List; import java.util.Scanner; public class BooksCRUD { static List<Book> list=new ArrayList<Book>(); static{ Book book1=new Book(1,"语文",30); Book book2=new Book(2,"数学",25); Book book3=new Book(3,"英语",31); list.add(book1); list.add(book2); list.add(book3); } public static void search(){ for(Book book4:list){ System.out.println(book4); } } public static void change(){ System.out.println("请输入需要修改的图书编号"); Integer 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"); } } } public 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){ } } public 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"); } } 复制代码 复制代码 package happy; import java.util.List; import java.util.ArrayList; import java.util.Scanner; public class Ui { private static BooksCRUD b = new BooksCRUD(); 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: b.add(); break; case 2: b.del(); break; case 3: b.change(); break; case 4: b.search(); break; case 5: System.out.println("退出成功"); return; default:System.out.println("输入错误请重新输入"); break; } } } }
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 language="java" import="java.util.*" pageEncoding="utf-8"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <%@page import="BookPackage.Book"%> <html> <head> </head> <body> 图书信息:<br/> <% ArrayList<Book> booklist=new ArrayList<Book>(); Book book1=new Book(1,"文言文",20); Book book2=new Book(2,"论语", 30); Book book3=new Book(3,"散文", 10); booklist.add(book1); booklist.add(book2); booklist.add(book3); for (int i = 0; i < booklist.size(); i++) { Book b=booklist.get(i); int id=b.getId(); String name=b.getName(); double price=b.getPrice(); out.print("图书编号:"+id+",图书名称:"+name+",图书价格为:"+price+"<br>"); } %> </body> </html>
3.在MySQL中创建Book表,里面id,name,price,
用命令实现,
添加一个图书,
根据名称删除图书,
把所有名称是“我”开头的图书删除,
删除全部图书,
把20元以上的图书价格都修改为18.8,
查看全部图书,
查看价格高于10块钱的全部图书
create database books; use books; create table book( id int(10), name varchar(10), price float ); insert into book values('1','呜呜呜','01.11'); insert into book values('2','book2','22.22'); 把20以上的价格修改成18.8 update book set price=18.8 where price>20; 查找所以书 select * from book; 查看价格高于10块的全部图书 select * from book where price>10; 把所有名称是“我”开头的图书删除 delete from book where name like '呜%'; 删除全部图书 delete from book;