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

复制代码
package work;

public class Book {
    private String id;
    private String name;
    private double 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;
    }

    public Book(String string, String name, double price) {
        super();
        this.id = string;
        this.name = name;
        this.price = price;
    }

    public Book() {
        super();
    }
}
package work;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class BookTest {
    static List<Book> listbooks = new ArrayList<Book>();

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        creatBookList();
        menu();

    }

    public static void creatBookList() {
        // TODO Auto-generated method stub
        Book b1 = new Book("001", "微机原理与接口技术", 49.8);
        listbooks.add(b1);
        Book b2 = new Book("002", "JSP实用教程", 59.8);
        listbooks.add(b2);
        Book b3 = new Book("003", "JavaScript", 49.8);
        listbooks.add(b3);
    }

    public static void menu() {
        for (;;) {
            System.out.println("************************");
            System.out.println("*       1.添加图书          *");
            System.out.println("*       2.修改图书          *");
            System.out.println("*       3.删除图书          *");
            System.out.println("*       4.查询图书          *");
            System.out.println("*       5.退出程序          *");
            System.out.println("************************");
            int a = inputInt("请选择你的操作:");
            switch (a) {
            case 1:
                addBook();
                break;
            case 2:
                updateBook();
                break;
            case 3:
                delBook();
                break;
            case 4:
                findBook();
                break;
            case 5:
                return;
            default:
                System.out.println("输入错误,请重新输入");
                break;
            }
        }
    }

    private static void findBook() {
        // TODO Auto-generated method stub
        System.out.println("id   图书名称  图书价格");
        for (Book book : listbooks) {
            System.out.println(book.getId() + " " + book.getName() + "    "
                    + book.getPrice());
        }

    }

    private static void delBook() {
        // TODO Auto-generated method stub
        String id = inputStr("请输入要删除图书的id");
        for (int i = 0; i < listbooks.size(); i++) {
            Book book = listbooks.get(i);
            if (id.equals(book.getId())) {
                listbooks.remove(i);
            }
        }

    }

    private static void updateBook() {
        // TODO Auto-generated method stub
        String id = inputStr("请输入要修改的图书id");
        for (int i = 0; i < listbooks.size(); i++) {
            Book book = listbooks.get(i);
            if (id.equals(book.getId())) {
                book.setName(inputStr("请输入修改后的图书名称:"));
                book.setPrice(inputDouble("请输入修改后的图书价格"));
                listbooks.remove(i);
                listbooks.add(i, book);
            }
        }

    }

    private static void addBook() {
        // TODO Auto-generated method stub
        String id = inputStr("请输入要添加的图书id");
        String name = inputStr("请输入要添加的图书名称");
        double price = inputDouble("请输入要添加的图书价格");
        Book book = new Book(id, name, price);
        listbooks.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();
    }
}
复制代码

 

 

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。

复制代码
 1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
 2 <%@page import="com.gd.entity.Book"%>
 3 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
 4 <html>
 5 <head>
 6 </head>
 7 
 8 <body>
 9     <%
10         List<Book> list = new ArrayList<Book>();
11         Book b1=new Book(1 "JavaScript     " 59.8);
12         Book b2=new Book(2 "Android移动应用 " 49.9);
13         Book b3=new Book(3 "信息系统分析与设计" 49.8);
14         list.add(b1);
15         list.add(b2);
16         list.add(b3);
17         for (int i = 0; list != null && i < list.size(); i++) {
18             out.print(list.get(i).getId() + "." + list.get(i).getName()
19                     + "," + list.get(i).getPrice() + "<br>");
20         }
21     %>
22 </body>
23 </html>
复制代码

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

复制代码
 create database Book;
 use Book;

create table book(
     id int(10) auto_increment primary key,
     name varchar(50),
     price double(6,2));

insert into Book(id,name,price)values(1,"天才在左疯子在右",5);
 insert into Book(id,name,price)values(2,"人间失格",45);
 insert into Book(id,name,price)values(3,"活着",15);
 insert into Book(id,name,price)values(4,"三体",145);
 insert into Book(id,name,price)values(5,"西游记",50);
复制代码
posted @ 2022-05-01 17:09  刘姝彤  阅读(35)  评论(0编辑  收藏  举报