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
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;

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

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 i, String name, double price) {
  super();
  this.id = i;
  this.name = name;
  this.price = price;
 }
 public Book() {
  super();
  // TODO Auto-generated constructor stub
 }
}

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

public class sc {
    static java.util.List<Book> list=new ArrayList<Book>();
    static{
        Book book1=new Book(1,"骆驼祥子",55);
        Book book2=new Book(2,"我的爱人",18);
        Book book3=new Book(3,"老人与海",35);
        list.add(book1);
        list.add(book2);
        list.add(book3);
    }
    
    
    
    
    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:
                add();        
                break;
            case 2:
                del();
                break;
            case 3:
                change();
                break;
            case 4:
                search();
                break;
            case 5:
                System.out.println("退出成功");
                return;
            }
    }
        }
    private static void search(){
        for(Book book4:list){
            System.out.println(book4);
        }
    }
    private static void change(){
        System.out.println("请输入需要修改的图书编号");
        int 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");
            }
        }
    }
    private 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){
            
        }
    }
    private 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");
    }

}

.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>
  图书：<br>
<%

        ArrayList<Book> list=new ArrayList<Book>();
        Book book1=new Book(1,"骆驼祥子",55);
        Book book2=new Book(2,"我的爱人",18);
        Book book3=new Book(3,"老人与海",35);
        
        list.add(book1);
        list.add(book2);
        list.add(book3);
        for (int i = 0; i < list.size(); i++) {
            Book b=list.get(i);
            int id=b.getId();
            String name=b.getName();
            double price=b.getPrice();
            out.print("id："+id+" ，   书名为："+name+"   ，价格为："+price);
            %><br><% 
        }
        
    %>

  </body>
</html>

#查询所有书籍信息
SELECT*
FROM Book

#查询价格大于10的书籍信息
SELECT*
FROM Book 
WHERE price>10

#将价格大于20的书籍的价格改为18.8
update book set price=18.8 where price>20;

#删除我开头的书
DELETE
From Book 
WHERE name like'我%'

#根据名称删除图书
DELETE
FROM Book 
WHERE name='老人与海'

#删除所有书籍信息
DELETE from book;

#删除表
DROP table book;

posted @ 2022-04-29 18:17 宋驰阅读(26) 评论(0) 编辑收藏举报

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宋驰

第九周作业

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