第九周
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 Book; public class Book { private int id; private String name; private 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(); } }
package Book; import java.util.ArrayList; import java.util.List; import java.util.Scanner; public class main { static List<Book> list = new ArrayList<Book>(); static Scanner sc=new Scanner(System.in); public static void main(String[] args) { // TODO Auto-generated method stub Book book1 = new Book(1,"唐诗三百首",30); Book book2 = new Book(2,"中华上下五千年",45); Book book3 = new Book(3,"唐诗宋词",29.9); list.add(book1); list.add(book2); list.add(book3); show(); } public static void show() { System.out.println("请选择你需要的操作"); System.out.println("1.添加图书"); System.out.println("2.查询图书"); System.out.println("3.修改图书"); System.out.println("4.删除图书"); System.out.println("============================"); main(); } public static void main() { int i=sc.nextInt(); switch (i) { case 1:add(); break; case 2:select(); break; case 3:updata(); break; case 4:del(); break; default: break; } } private static void del() { // TODO Auto-generated method stub System.out.println("请输入图书id"); int id=sc.nextInt(); for (int i = 0; i < list.size(); i++) { if (id == list.get(i).getId()) { list.remove(i); System.out.println("删除成功"); } } for (int i = 0; i < list.size(); i++) { Book b1=list.get(i); System.out.println("id为"+b1.getId()+":"+b1.getName()+"¥价格为"+b1.getPrice()); } System.out.println("-------------------------------"); show(); } private static void updata() { // TODO Auto-generated method stub System.out.println("请输入图书id"); int id=sc.nextInt(); for (int i = 0; i < list.size(); i++) { if (id == list.get(i).getId()) { list.remove(i); System.out.println("请输入图书name"); String name=sc.next(); System.out.println("请输入图书price"); int price=sc.nextInt(); Book b=new Book(id,"name",price); b.setId(id); b.setName(name); b.setPrice(price); list.add(b); System.out.print("操作成功为"); } } for (int i = 0; i < list.size(); i++) { Book b1=list.get(i); System.out.println("id为"+b1.getId()+":"+b1.getName()+"¥价格为"+b1.getPrice()); } System.out.println("-------------------------------"); show(); } private static void select() { // TODO Auto-generated method stub System.out.println("请输入图书id"); int id=sc.nextInt(); for (int i = 0; i < list.size(); i++) { if (id == list.get(i).getId()) { System.out.println("查询结果为"); Book b1=list.get(i); System.out.println("id为"+b1.getId()+"\n"+b1.getName()+" ¥价格为"+b1.getPrice()); } } System.out.println("-------------------------------"); show(); } private static void add() { // TODO Auto-generated method stub System.out.println("请输入图书id"); int id=sc.nextInt(); System.out.println("请输入图书name"); String name=sc.next(); System.out.println("请输入图书price"); double price=sc.nextDouble(); Book b=new Book(id,"name",price); b.setId(id); b.setName(name); b.setPrice(price); list.add(b); for (int i = 0; i < list.size(); i++) { Book b1=list.get(i); System.out.println("id为"+b1.getId()+":"+b1.getName()+"¥价格为"+b1.getPrice()); } System.out.println("-------------------------------"); show(); } }
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="Book.Book"%> <%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> </head> <body> <% List<Book> list = new ArrayList<Book>(); Book book = new Book(); Book book1 = new Book(1, "liu", 444); Book book2 = new Book(2, "de", 555); Book book3 = new Book(3, "pu", 666); list.add(book1); list.add(book2); list.add(book3); 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,
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