java 数据库试卷及答案

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mob64ca140e76c8 2024-07-15 07:50:31

文章标签 java 数据库试卷及答案 mysql jdbc jsp 数据库 文章分类 Java 后端开发

实验九 JDBC数据库访问二

一、实验目标：

掌握并熟练使用JDBC查询数据库
区分精确查询与模糊查询，掌握预处理语句。

二、实验内容：

在实验八的基础上完成
（必做）完成全部查询和条件查询
用MVC模式完成查询全部记录及按关键字商品号查询（精确查询）。
（选作）：按商品名模糊查询，按某个排序查询或者输入行号，定位某条记录等。。。
JavaBean的设计要求：
Message.java：数据类，与表相对应的数据模型
MessageDAO.java:业务类，所有和表相关的操作如查询、添加、删除、修改等操作都封装在此类中。

三、注意事项

⒈认真填写实验报告
⒉遵守实验室各项制度，服从实验指导教师的安排
⒊按规定的时间完成实验

实验十 JDBC数据库访问三

一、实验目标：

掌握并熟练使用JDBC操作数据库：添加，删除及修改。
练习使用数据库连接池及其他相关技术。

二、实验内容：

在添加记录的基础上，实现对表记录的更新、删除；
a) 用MVC模式来完成
b) 要考虑操作过程中的数据安全性问题，比如添加、更新记录要检查用户名，删除如果是基于编号的删除要考虑编号是否存在
（选做）尝试用数据连接池来完成数据库的连接。
用DAO设计模式对程序进行重构。

三、注意事项

⒈认真填写实验报告
⒉遵守实验室各项制度，服从实验指导教师的安排
⒊按规定的时间完成实验

项目代码：

package cn.jdbc.domain;

public class Student 
{
	
	private String sno; // 学号
	
	private String sname; // 姓名
	
	private int sage; // 年龄
	
	public String getSno() 
	{
		return sno;
	}
	public void setSno(String sno) 
	{
		this.sno = sno;
	}
	public String getSname() 
	{
		return sname;
	}
	public void setSname(String sname) 
	{
		this.sname = sname;
	}
	public int getSage() 
	{
		return sage;
	}
	public void setSage(int sage) 
	{
		this.sage = sage;
	}

}

package cn.jdbc.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;


import cn.jdbc.domain.Student;
import cn.jdbc.utils.Utils;

/*
 * 完成对数据库的增删改查操作
 */
public class StudentDao {
 //为学生表添加数据
    public boolean insert(Student student) {
        Connection conn = null;
        PreparedStatement stmt = null;
        ResultSet rs = null;
        try {
            // 获得数据的连接
            conn = Utils.getConnection();
            // SQL语句
            String sql="insert into student values(?,?,?)";
            //得到预编译对象
            stmt=conn.prepareStatement(sql);
            stmt.setString(1, student.getSno());
            stmt.setString(2, student.getSname());
            stmt.setInt(3, student.getSage());
            int num = stmt.executeUpdate();
            if (num > 0) {
                return true;
            }
            return false;
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            Utils.release(rs, stmt, conn);
        }
        return false;
    }
 //查询所有数据
    public List < Student > findAll() {
        Connection conn = null;
        PreparedStatement stmt = null;
        ResultSet rs = null;
        List < Student > list = new ArrayList < Student > ();
        try {
            // 获得数据的连接
            conn = Utils.getConnection();
            // SQL语句
            String sql="select * from student";
            //得到预编译对象
            stmt=conn.prepareStatement(sql);
            rs = stmt.executeQuery();
            // 处理结果集,遍历rs结果集
            while (rs.next()) {
                Student student = new Student();
                student.setSno(rs.getString("sno"));
                student.setSname(rs.getString("sname"));
                student.setSage(rs.getInt("sage"));
                list.add(student);
            }
            return list;
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            Utils.release(rs, stmt, conn);
        }
        return null;
    }
 // 根据id查找指定的student
    public Student find(String id) {
        Connection conn = null;
        PreparedStatement stmt = null;
        ResultSet rs = null;
        Student student = new Student();
        try {
            // 获得数据的连接
            conn = Utils.getConnection();
            //SQL语句
            String sql = "select * from student where sno=?";
            //得到预编译对象
            stmt=conn.prepareStatement(sql);
            stmt.setString(1, id);
            rs = stmt.executeQuery();
            // 处理结果集
            while (rs.next()) {                
                student.setSno(rs.getString("sno"));
                student.setSname(rs.getString("sname"));
                student.setSage(rs.getInt("sage"));
                return student;
            }
            return null;
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            Utils.release(rs, stmt, conn);
        }
        return null;
    }
 //删除学生数据
    public boolean delete(String id){
      Connection conn = null;
      PreparedStatement stmt = null;
      ResultSet rs = null;
      try {
          // 获得数据的连接
          conn = Utils.getConnection();
          //sql语句          
          String sql = "delete from student where sno=?";
          //获取预处理对象        
          stmt= conn.prepareStatement(sql);
          stmt.setString(1, id);
          int num = stmt.executeUpdate();
          if (num > 0) {
              return true;
          }
          return false;
      } catch (Exception e) {
          e.printStackTrace();
      } finally {
          Utils.release(rs, stmt, conn);
      }
      return false;
    }
 // 修改用户
    public boolean update(Student student) {
        Connection con = null;
        PreparedStatement stmt = null;
        ResultSet rs = null;
        try {
            //获得数据的连接
            con = Utils.getConnection();
            //sql语句
            String sql="update student set sname=?,sage=? where sno =?";
            //得到预编译对象
            stmt=con.prepareStatement(sql);
            stmt.setString(1, student.getSname());
            stmt.setInt(2, student.getSage());
            stmt.setString(3, student.getSno());
            int num = stmt.executeUpdate();
            if (num > 0) {
                return true;
            }
            return false;
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            Utils.release(rs, stmt, con);
        }
        return false;
    }
}

package cn.jdbc.servlet;

import java.io.IOException;

import java.util.ArrayList;
import java.util.List;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import cn.jdbc.dao.StudentDao;
import cn.jdbc.domain.Student;


public class Display extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
	public Display() {
		super();
	}

	/**
	 * Destruction of the servlet. <br>
	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	/**
	 * The doGet method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException 
	{
		request.setCharacterEncoding("UTF-8");
		
		//获取数据库操作的对象
		StudentDao dao = new StudentDao();
		//获取数组对象
		List<Student> list = new ArrayList<Student>();
		
		//获取查询的学号
		String search_sno = request.getParameter("search_no");
		
		//获取添加的数据
		String add_sno = request.getParameter("add_sno");
		String add_sname = request.getParameter("add_sname");
		String add_sage = request.getParameter("add_sage");
		
		//获取修改的数据
		String cg_sno = request.getParameter("cg_sno");
		String cg_sname = request.getParameter("cg_sname");
		String cg_sage = request.getParameter("cg_sage");
		
		//获取删除的学号
		String del_sno = request.getParameter("del_sno");
		
		//查询数据
		if(search_sno!=null){
			Student student= dao.find(search_sno);	
			list.add(student);
			search_sno="";
		}else{//显示所有的数据
			list=dao.findAll();
		}
		//添加数据
		if(add_sage!=null){
			Student student = new Student();
			student.setSno(add_sno);
			student.setSname(add_sname);
			student.setSage(Integer.parseInt(add_sage));
			dao.insert(student);
			list=dao.findAll();
			add_sno="";
			add_sname="";
			add_sage="";
		}
		//修改数据
		if(cg_sage!=null){
			Student student = new Student();
			student.setSno(cg_sno);
			student.setSname(cg_sname);
			student.setSage(Integer.parseInt(cg_sage));
			dao.update(student);
			list=dao.findAll();
			cg_sno="";
			cg_sname="";
			cg_sage="";
		}
		//删除数据
		if(del_sno!=null){
			dao.delete(del_sno);
			list=dao.findAll();
			del_sno="";
		}
		//传递数组到jsp页面		
		request.setAttribute("list", list);
		request.getRequestDispatcher("index.jsp").forward(request, response);
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	

	

	/**
	 * The doPost method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to post.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
      protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException 
      {
	// TODO Auto-generated method stub
	doGet(request, response);
}

	/**
	 * Initialization of the servlet. <br>
	 *
	 * @throws ServletException if an error occurs
	 */
	public void init() throws ServletException {
		// Put your code here
	}

}

package cn.jdbc.utils;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class Utils {
// 加载驱动，并建立数据库连接
	public static Connection getConnection() throws SQLException,
				ClassNotFoundException {
//		         加载驱动
			Class.forName("com.mysql.cj.jdbc.Driver");
//			获取数据库连接
			String url = "jdbc:mysql://localhost:3306/javaweb?useSSL=false&serverTimezone=UTC&allowPublicKeyRetrieval=true&useUnicode=true&characterEncoding=utf-8";
//			用户名
			String username = "root";
//			密码
	    	String password = "1234";
			Connection conn = DriverManager.getConnection(url, username, 
					password);
			return conn;
		}
	// 关闭数据库连接，释放资源
	public static void release(ResultSet rs, Statement stmt, Connection conn) {
		if (rs != null) {
			try {
				rs.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
			rs = null;
		}
		if (stmt != null) {
			try {
				stmt.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
			stmt = null;
		}
		if (conn != null) {
			try {
				conn.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
			conn = null;
		}
		
	}
}

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8" contentType="text/html; charset=UTF-8"%>
<%@ page import="java.io.*,java.util.*,java.sql.*"%>
<%@ page import="javax.servlet.http.*,javax.servlet.*" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/sql" prefix="sql"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML>
<html>
  <head>
    <base href="<%=basePath%>">
    
    <style type="text/css">
    body
    {
	text-align: center;
    }
    </style>
    
    <title>学生数据</title>
    
    <meta charset="UTF-8">
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	<!--
	<link rel="stylesheet" type="text/css" href="styles.css">
	-->

  </head>
  
  <body>
 <h2>学生信息查询系统</h2>

    <table align="center" border="1" cellpadding="0" cellspacing="0" width="60%">
        <thead>
            <tr>
                <th>学号</th>
                <th>姓名</th>
                <th>年龄</th>
            </tr>
        </thead>
        <tbody>
        	 <c:forEach items="${list}" var="i">
            <tr >
               	<td>${i.sno}</td>
               	<td>${i.sname}</td>
               	<td>${i.sage}</td>
            </tr>
            </c:forEach> 
        </tbody>
    </table>
    
    <br><br><br>
    <table align="center" border="0" cellpadding="0" cellspacing="0" width="40%">
    	<tr>
    		<td><a href="display.do">首页</a></td>
    		<td><a href="inquire.jsp">查询</a></td>
    		<td><a href="add.jsp">添加</a></td>
    		<td><a href="amend.jsp">修改</a></td>
    		<td><a href="delete.jsp">删除</a></td>
    	</tr>
    </table>

</body>
</html>

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8" contentType="text/html; charset=UTF-8"%>
<%@ page import="java.io.*,java.util.*,java.sql.*"%>
<%@ page import="javax.servlet.http.*,javax.servlet.*" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/sql" prefix="sql"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML>
<html>
  <head>
    <base href="<%=basePath%>">
    
    <style type="text/css">
    body
    {
	text-align: center;
    }
    </style>
    
    <title>修改功能</title>
    
    <meta charset="UTF-8">
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	<!--
	<link rel="stylesheet" type="text/css" href="styles.css">
	-->

  </head>
<body align="center">
    <h3>修改数据</h3>
    <form action="display.do" method="post">
        <label>学号：</label>
        <input type="text" name="cg_sno"><br><br>
        <label>姓名：</label>
        <input type="text" name="cg_sname"><br><br>
        <label>年龄：</label>
        <input type="text" name="cg_sage">
        <br><br>                
        <input type="submit" value="修改"><br><br>     
        <a href="display.do">返回首页</a><br>  
    </form>
</body>
</html>

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8" contentType="text/html; charset=UTF-8"%>
<%@ page import="java.io.*,java.util.*,java.sql.*"%>
<%@ page import="javax.servlet.http.*,javax.servlet.*" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/sql" prefix="sql"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML>
<html>
  <head>
    <base href="<%=basePath%>">
    
    <style type="text/css">
    body
    {
	text-align: center;
    }
    </style>
    
    <title>查询功能</title>
    
    <meta charset="UTF-8">
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	<!--
	<link rel="stylesheet" type="text/css" href="styles.css">
	-->

  </head>
<body align="center">
	<h3>删除数据</h3>
    <form action="display.do" method="post">
        <label>删除数据学生的学号：</label>
        <input type="text" name="del_sno">
        <br><br>
        <input type="submit" value="删除"><br><br>    
        <a href="display.do">返回首页</a><br>    
    </form>
</body>
</html>

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8" contentType="text/html; charset=UTF-8"%>
<%@ page import="java.io.*,java.util.*,java.sql.*"%>
<%@ page import="javax.servlet.http.*,javax.servlet.*" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/sql" prefix="sql"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML>
<html>
  <head>
    <base href="<%=basePath%>">
    
    <style type="text/css">
    body
    {
	text-align: center;
    }
    </style>
    
    <title>增加功能</title>
    
    <meta charset="UTF-8">
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	<!--
	<link rel="stylesheet" type="text/css" href="styles.css">
	-->

  </head>
<body align="center">
	<h3>添加数据</h3>
    <form action="display.do" method="post">
        <label>学号：</label>
        <input type="text" name="add_sno"> <br><br>
        <label>姓名：</label>
        <input type="text" name="add_sname"> <br><br>
        <label>年龄：</label>
        <input type="text" name="add_sage"> 
        <br><br>               
        <input type="submit" value="添加"><br><br>
        <a href="display.do">返回首页</a><br>       
    </form>
</body>
</html>

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8" contentType="text/html; charset=UTF-8"%>
<%@ page import="java.io.*,java.util.*,java.sql.*"%>
<%@ page import="javax.servlet.http.*,javax.servlet.*" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/sql" prefix="sql"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML>
<html>
  <head>
    <base href="<%=basePath%>">
    
    <style type="text/css">
    body
    {
	text-align: center;
    }
    </style>
    
    <title>查询功能</title>
    
    <meta charset="UTF-8">
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	<!--
	<link rel="stylesheet" type="text/css" href="styles.css">
	-->

  </head>
<body align="center">
	 <h3>查询数据</h3>
    <form action="display.do" method="post">
        <label>查询的学号：</label>
        <input type="text" name="search_no">
        <br><br>
        <input type="submit" value="查询"> 
        <br><br>
        <a href="display.do">返回首页</a><br>      
    </form>
</body>
</html>

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" 
	xmlns="http://java.sun.com/xml/ns/javaee" 
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
	http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
  <display-name></display-name>
  <servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>Display</servlet-name>
    <servlet-class>cn.jdbc.servlet.Display</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>Display</servlet-name>
    <url-pattern>/display.do</url-pattern>
  </servlet-mapping>	
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>