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
package pag; public class Book { private String id; private String name; private double price; public Book() { } public Book(String id, String name, double price) { this.id = id; this.name = name; this.price = price; } public String getId() { return id; } public void setId(String 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; } }
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 pag; import java.util.ArrayList; import java.util.List; import java.util.Scanner; public class Test { static List<Book> lbs = new ArrayList<Book>(); static { Book b1 = new Book("001", "book1", 70.9); lbs.add(b1); Book b2 = new Book("002", "book2", 49.9); lbs.add(b2); Book b3 = new Book("003", "book3", 99.9); lbs.add(b3); } /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub mnue(); } public static void mnue() { for (;;) { System.out.println("***********************"); System.out.println("* 1、添加图书 *"); System.out.println("* 2、删除图书 *"); System.out.println("* 3、修改图书 *"); System.out.println("* 4、查询所有图书 *"); System.out.println("* 5、查询一本图书 *"); System.out.println("* 0、退出程序 *"); System.out.println("***********************"); int i = inputInt("请输入要选择的操作:"); switch (i) { case 1: addBook(); break; case 2: delBook(); break; case 3: updateBook(); break; case 4: findAllBook(); break; case 5: findBookByName(); break; case 0: return; default: System.out.println("输入错误,请重新输入"); break; } } } private static void findBookByName() { String name = inputStr("请输入要查找的图书名称"); int index = 0; System.out.println("id\t图书名称\t价格"); for (Book book : lbs) { if (name.equals(book.getName())) { System.out.println(book.getId() + "\t" + book.getName() + "\t" + book.getPrice()); } index++; } } private static void findAllBook() { System.out.println("id\t图书名称\t价格"); for (Book book : lbs) { System.out.println(book.getId() + "\t" + book.getName() + "\t" + book.getPrice()); } } private static void updateBook() { String id = inputStr("请输入要修改的图书id"); int index = 0; for (Book book : lbs) { if (id.equals(book.getId())) { book.setName(inputStr("请输入修改后的名称:")); book.setPrice(inputDouble("请输入修改后的价格:")); lbs.remove(index); lbs.add(index, book); } index++; } } private static void delBook() { String id = inputStr("请输入要删除的图书id"); for (int i = 0;i < lbs.size();i++) { if (id.equals(lbs.get(i).getId())) { lbs.remove(i); } } } private static void addBook() { String id = inputStr("请输入图书id"); String name = inputStr("请输入图书名称"); double price = inputDouble("请输入图书价格"); Book book = new Book(id, name, price); lbs.add(book); } public static String inputStr(String msg) { System.out.print(msg); return new Scanner(System.in).nextLine(); } public static int inputInt(String msg) { System.out.print(msg); return new Scanner(System.in).nextInt(); } public static double inputDouble(String msg) { System.out.print(msg); return new Scanner(System.in).nextDouble(); } }
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="pag.Book"%> <%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <!DOCTYPE HTML > <html> <head> </head> <body> <% List<Book> listbooks = new ArrayList<Book>(); Book b1 = new Book("001", "book1", 70.9); listbooks.add(b1); Book b2 = new Book("002", "book2", 40.9); listbooks.add(b2); Book b3 = new Book("003", "book3", 99.9); listbooks.add(b3); for (int i = 0; listbooks != null && i < listbooks.size(); i++) { out.print(listbooks.get(i).getId() + ": " + listbooks.get(i).getName() + " " + listbooks.get(i).getPrice() + "<br>"); } %> </body> </html>
3.在MySQL中创建Book表,里面id,name,price,
用命令实现,
添加5个图书,
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
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。
insert into 表名(列,列,列)values(值,值,值)
delete from 表名 where 删除条件
update 表名 set列名=更新值 where 更新条件
select 列,列,列 …… from 表 where 查询条件
在MYSQL中创建Book表,里面id,name,price create table book( -> id int(10) auto_increment primary key, -> name varchar(50), -> price double(5,1)); 添加5个图书 insert into Book(id,name,price)values(001,"book1",9); insert into Book(id,name,price)values(002,"book2",15); insert into Book(id,name,price)values(003,"book3",30); insert into Book(id,name,price)values(004,"book4",25); insert into Book(id,name,price)values(005,"book5",19.9); 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 '我%'; 删除全部图书 delete from book;