jdbc 简易 模板

 1 package org.db;
 2
 3 import java.sql.Connection;
 4 import java.sql.DriverManager;
 5 import java.sql.SQLException;
 6
 7 public class DBConn {
 8
 9 //    public final static String URL = "jdbc:mysql://localhost:3306/test?useSSL=false";
10     public final static String URL = "jdbc:mysql://localhost:3306/test?characterEncoding=utf8"; //可以指定jdbc编码方式
11     public final static String USERNAME = "root";
12     public final static String PASSWORD = "000000";
13     public final static String DRIVER = "com.mysql.jdbc.Driver";
14
15     public static Connection conn;
16     public static Connection getConn(){
17         try {
18             Class.forName(DRIVER);
19             conn = DriverManager.getConnection(URL, USERNAME, PASSWORD);
20             if (conn!=null) {
21                 System.out.println("连接成功");
22             }
23             return conn;
24         } catch (Exception e) {
25             e.printStackTrace();
26             System.out.println("连接失败");
27             return null;
28         }
29     }
30     public static void closeConn(){
31         try {
32             if(conn!=null){
33                 conn.close();
34             }
35         } catch (SQLException e) {
36             e.printStackTrace();
37         }
38     }
39 }

 1 package org.test;
 2
 3 import java.sql.Connection;
 4 import java.sql.PreparedStatement;
 5 import java.sql.ResultSet;
 6 import java.sql.SQLException;
 7
 8 import org.db.DBConn;
 9 import org.model.Login;
10
11 public class test {
12
13     public static void main(String[] args) {
14         Connection conn = DBConn.getConn();
15         if (conn!=null) {
16             System.out.println("连接成功");
17             try {
18                 conn = DBConn.getConn();
19                 String sql = "select id,name,password,role from mbook where name=? and password=?";
20                 PreparedStatement ps = conn.prepareStatement(sql);
21                 ps.setString(1,"张三");
22                 ps.setString(2,"000000");
23                 ResultSet rs = ps.executeQuery();
24
25                     while (rs.next()) {
26                     Login login = new Login();
27                     login.setId(rs.getInt(1));
28                     login.setName(rs.getString(2));
29                     login.setPassword(rs.getString(3));
30                     login.setRole(rs.getBoolean(4));
31                     System.out.println("得到数据："+login);
32                     }
33             } catch (SQLException e) {
34                 e.printStackTrace();
35             }finally{
36                 DBConn.closeConn();
37             }
38         }
39     }
40 }