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 nn; 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(); } }
package nn; 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, "English", 99); Book b2 = new Book(2, "Math", 66.66); Book b3 = new Book(3, "Chinese", 88); 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.添加图书"); System.out.println("2.删除图书"); System.out.println("3.修改图书"); System.out.println("4.查询图书"); 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("添加图书的编号:"); book.setId(new Scanner(System.in).nextInt()); System.out.println("添加图书的名称:"); book.setName(new Scanner(System.in).next()); System.out.println("添加图书的价格:"); book.setPrice(new Scanner(System.in).nextDouble()); list.add(book); System.out.println("添加成功"); show(list, book); break; case 2: System.out.println("输入要删除图书的名称:"); 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("删除成功"); show(list, book); break; case 3: System.out.println("输入要修改图书的编号:"); 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("输入修改后图书的名称:"); String name1=new Scanner(System.in).next(); System.out.println("输入修改后图书的价格:"); double price1=new Scanner(System.in).nextDouble(); Book b=new Book(k,name1,price1); list.add(b); break; } } System.out.println("修改成功"); 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; } } }
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"%> <%@page import="nn.Book"%> <!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, "Math", 66); Book b2 = new Book(2, "English", 77.7); Book b3 = new Book(3, "Chinese", 88.88); 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));
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='Math';
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;