通过配置文件访问数据库

时间:2021-05-22 10:41:50   收藏:0   阅读:24
 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html>
 4 <html>
 5 <head>
 6 <meta charset="UTF-8">
 7 <title>Insert title here</title>
 8 </head>
 9 <body>
10 <form action="loginCheck" method="post">
11     用户名:<input type="text" placeholder="请输入用户名" name="uname"><br>
12     密码:<input type="password" placeholder="请输入密码" name="pwd"><br>
13     <input type="submit" value="登录">
14     <input type="reset" value="重置">
15 </form>
16 </body>
17 </html>
1 url=jdbc:mysql://localhost:3306/db3
2 user=root
3 password=root
4 driver=com.mysql.jdbc.Driver
  1 package util;
  2 
  3 import java.io.FileNotFoundException;
  4 import java.io.FileReader;
  5 import java.io.IOException;
  6 import java.net.URL;
  7 import java.sql.Connection;
  8 import java.sql.DriverManager;
  9 import java.sql.ResultSet;
 10 import java.sql.SQLException;
 11 import java.sql.Statement;
 12 import java.util.Properties;
 13 
 14 /** 
 15  * <p>Title: JDBCUtils</p>  
 16  * <p>Description: JDBC工具类</p>  
 17  * @author: 丁帅帅
 18  * @date: 2021-5-20 16:06:47
 19  * @version v1.0 
 20  */
 21 public class JDBCUtils {
 22        private static String url;
 23        private static String user;
 24        private static String password;
 25        private static String driver;
 26        
 27        static {
 28      try {
 29            Properties pro =new Properties();
 30            ClassLoader classLoader=JDBCUtils.class.getClassLoader();
 31            URL res=classLoader.getResource("jdbc.properties");
 32            String path=res.getPath();
 33           
 34             pro.load(new FileReader(path));
 35             url=pro.getProperty("url");
 36             user=pro.getProperty("user");
 37             password=pro.getProperty("password");
 38             driver=pro.getProperty("driver");
 39             
 40             Class.forName(driver);
 41         } catch (FileNotFoundException e) {
 42             
 43             e.printStackTrace();
 44         } catch (IOException e) {
 45             
 46             e.printStackTrace();
 47         } catch (ClassNotFoundException e) {
 48             
 49             e.printStackTrace();
 50         }
 51        }
 52        
 53        public static Connection getConnection() throws SQLException {
 54            return DriverManager.getConnection(url,user,password);
 55        }
 56        
 57        
 58        public static void close(Statement stmt,Connection conn) {
 59            if(stmt!=null) {
 60                try {
 61                 stmt.close();
 62             } catch (SQLException e) {
 63                 // TODO Auto-generated catch block
 64                 e.printStackTrace();
 65             }
 66                if(conn!=null) {
 67                    try {
 68                     conn.close();
 69                 } catch (SQLException e) {
 70                     // TODO Auto-generated catch block
 71                     e.printStackTrace();
 72                 }
 73                }
 74                
 75                
 76            }
 77        }
 78        
 79        public static void close(ResultSet rs,Statement pstmt,Connection conn) {
 80            if(rs!=null) {
 81                try {
 82                 rs.close();
 83             } catch (SQLException e) {
 84                 
 85                 e.printStackTrace();
 86             }
 87            }
 88            
 89            if(pstmt!=null) {
 90                try {
 91                 pstmt.close();
 92             } catch (SQLException e) {
 93                 
 94                 e.printStackTrace();
 95             }
 96                if(conn!=null) {
 97                    try {
 98                     conn.close();
 99                 } catch (SQLException e) {
100                     
101                     e.printStackTrace();
102                 }
103                }   
104                
105            }
106        }
107        
108 }
 1 package javabean;
 2 
 3 import java.sql.Connection;
 4 import java.sql.PreparedStatement;
 5 import java.sql.ResultSet;
 6 import java.sql.SQLException;
 7 
 8 import util.JDBCUtils;
 9 
10 /** 
11  * <p>Title: user</p>  
12  * <p>Description: </p>  
13  * @author: 丁帅帅
14  * @date: 2021-5-21 22:23:49
15  * @version v1.0 
16  */
17 public class user {
18      private String name;
19      private int password;
20      private Connection conn=null;
21      private PreparedStatement pstmt=null;
22      private ResultSet rs=null;
23     public user(String name, int password) {
24         this.name = name;
25         this.password = password;
26     }
27     public String getName() {
28         return name;
29     }
30     public void setName(String name) {
31         this.name = name;
32     }
33     public int getPassword() {
34         return password;
35     }
36     public void setPassword(int password) {
37         this.password = password;
38     }
39     @Override
40     public String toString() {
41         return "user name=" + name + ", password=" + password;
42     }
43     public boolean login() {
44         try {
45             conn=JDBCUtils.getConnection();
46             String sql="select *from user where name=? and password=?";
47             pstmt=conn.prepareStatement(sql);
48             
49             pstmt.setString(1,name);
50             pstmt.setInt(2,password);
51             rs=pstmt.executeQuery();
52             /*
53              * if(rs.next()) { return true; }else { return false; }
54              */
55             return rs.next();
56         } catch (SQLException e) {
57             
58             e.printStackTrace();
59         }finally {
60             JDBCUtils.close(rs, pstmt, conn);
61         }
62         return false;
63     }
64      
65 }
 1 package com.servlet;
 2 
 3 import java.io.IOException;
 4 
 5 import javax.servlet.ServletException;
 6 import javax.servlet.annotation.WebServlet;
 7 import javax.servlet.http.HttpServlet;
 8 import javax.servlet.http.HttpServletRequest;
 9 import javax.servlet.http.HttpServletResponse;
10 
11 import javabean.user;
12 
13 
14 @WebServlet("/Jsp_Servlet/loginCheck")
15 public class LoginCheck extends HttpServlet{
16       @Override
17     protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
18         
19         doGet(req, resp);
20     }
21       @Override
22     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
23         String uname=req.getParameter("uname");
24         int pwd=Integer.parseInt(req.getParameter("pwd")) ;
25         user user = new user(uname, pwd);
26         boolean flag=user.login();
27         if(flag) {
28             req.setAttribute("name", uname);
29             req.getRequestDispatcher("Welcome.jsp").forward(req, resp);
30         }
31         else {
32             //System.out.println(user.toString());
33             req.getRequestDispatcher("login.jsp").forward(req, resp);
34         }
35             
36     }
37 }
 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html>
 4 <html>
 5 <head>
 6 <meta charset="UTF-8">
 7 <title>Insert title here</title>
 8 </head>
 9 <body>
10 <h1>欢迎您,<%=request.getAttribute("name") %></h1>
11 </body>
12 </html>

 

原文:https://www.cnblogs.com/dss-99/p/14797748.html

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