JDBC工具类实现登陆验证-Java(新手)

JDBC工具类：

 1 package cn.chuang.JdbcDome;
 2 
 3 import java.sql.*;
 4 
 5 public class JdbcUtilss {
 6     private static final String user = "root";
 7     private static final String r = "root";
 8     private static final String p = "root";
 9     private static final String url = "jdbc:mysql:///semployee";
10     private static final String DRIVER = "com.mysql.jdbc.Driver";
11     //注册驱动。
12     static{
13         try {
14             Class.forName(DRIVER);
15         } catch (ClassNotFoundException e) {
16             e.printStackTrace();
17         }
18     }
19     //得到数据库链接。
20     public static Connection getConnection() throws Exception {
21         return DriverManager.getConnection(url,r,p);
22     }
23 
24     //关闭链接，执行打开的资源。
25     public static void close(Connection conn,Statement stmt){
26         if (stmt!=null){
27             try {
28                 stmt.close();
29             } catch (Exception e) {
30                 e.printStackTrace();
31             }
32         }
33         if (conn!=null){
34             try {
35                 conn.close();
36             } catch (Exception e) {
37                 e.printStackTrace();
38             }
39         }
40     }
41     //关闭所有打开的资源。
42     public static void close(Connection conn, Statement stmt, ResultSet rs){
43         if (stmt!=null){
44             try {
45                 stmt.close();
46             } catch (Exception e) {
47                 e.printStackTrace();
48             }
49         }if (conn!=null){
50             try {
51                 conn.close();
52             } catch (Exception e) {
53                 e.printStackTrace();
54             }
55         }
56         if (rs!=null){
57             try {
58                 rs.close();
59             } catch (Exception e) {
60                 e.printStackTrace();
61             }
62         }
63     }
64 
65 }

利用JDBC工具类实现登陆验证：

 1 package cn.chuang.JdbcDome;
 2 
 3 import java.sql.Connection;
 4 import java.sql.PreparedStatement;
 5 import java.sql.ResultSet;
 6 import java.sql.Statement;
 7 import java.util.Scanner;
 8 
 9 public class JdbcUtilsUser {
10     public static void main(String[] args){
11         Scanner sc = new Scanner(System.in);
12         System.out.println("请输入用户名");
13         String name = sc.nextLine();
14 
15         System.out.println("请您输入密码");
16         String password = sc.nextLine();
17         login(name,password);
18     }
19     public static void login(String name,String password){
20         Connection conn = null;
21         PreparedStatement pre=null;
22         ResultSet rs = null;
23 
24         try {
25             conn = JdbcUtilss.getConnection();
26             String sql = "select * from zh where uname = '"+name+"' and upd = '"+password+"'" ;
27             pre = conn.prepareStatement(sql);
28             rs = pre.executeQuery();
29             System.out.println(sql);
30             if (rs.next()){
31                 System.out.println("登陆成功，欢迎您"+name);
32             }else{
33                 System.out.println("登录失败");
34             }
35         } catch (Exception e) {
36             e.printStackTrace();
37         }
38         finally {
39             JdbcUtilss.close(conn,pre,rs);
40         }
41     }
42 }