第七次作业4.27

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 abc;


	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, "默读", 120);
	        book b2 = new book(2, "一级律师", 90);
	        book b3 = new book(3, "Romeo and Juliet", 134);
	        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("请添加图书的编号:");
	            book.setId(new Scanner(System.in).nextInt());
	            System.out.println("请添加图书的名称:");
	            book.setName(new Scanner(System.in).next());
	            System.out.println("请添加图书的价格:");
	            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("请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("请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("请输入修改后图书的名称:");
	                    String name1=new Scanner(System.in).next();
	                    System.out.println("请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;
	        }
	    }

	}

  

package abc;

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();
	    }
	    

}

  

 

 

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="abc.book"%>
<!DOCTYPE HTML >
<html>
<head>
<title>My JSP 'index.jsp' starting page</title>
</head>
<body>
 
    <%
        List<book> list = new ArrayList<book>();
        book b1 = new book(1, "默读", 120);
        book b2 = new book(2, "一级律师", 90);
        book b3 = new book(3, "Romeo and Juliet", 134);
        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
insert into Book(id,name,price)values(1,"java",88);

  

根据名称删除图书,

delete from book where name='Romeo and Juliet';
 


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;

  

  

posted @ 2022-04-29 22:21  日夜不休  阅读(28)  评论(0编辑  收藏  举报