Java读取.properties配置文件并连接数据库

1、读取配置文件

1  //Properties集合 流对象读取键值对
2     public static void getNum() throws Exception {
3         Properties p=new Properties();
4         FileReader f=new FileReader("c:\\root.properties");
5         p.load(f);
6         f.close();
7     }

2、properties文件

url:jdbc:mysql://localhost:3306/qy97
name:"root"
password:"root"

3、数据库连接代码

package com.aaa.QuDong;

import java.io.FileReader;
import java.sql.*;
import java.util.Properties;

public class SQLEnc_Test {
    public static void main(String[] args) throws Exception {
        Properties p=new Properties();
        //获取文件里边的值
        FileReader f=new FileReader("c:\\root.properties");
        p.load(f);
        String url=p.getProperty("url");
        String user = p.getProperty("name");
        String root=p.getProperty("password");
        //通过值连接数据库
        Connection conn = SQLEns.jdbc_enc(url, user, root);
        String sql="select * from users where uname like '%郭敬明%'";
        System.out.println(conn);
        PreparedStatement pre =conn.prepareStatement(sql);
        ResultSet rs = pre.executeQuery();
        while (rs.next()){
            String name = rs.getString(2);
            String dsc = rs.getString(5);
            System.out.println("姓名："+name+"     描述："+dsc);
        }
        pre.close();
        conn.close();
        f.close();
    }
    //Properties集合 流对象读取键值对
    public static void getNum() throws Exception {
        Properties p=new Properties();
        FileReader f=new FileReader("c:\\root.properties");
        p.load(f);
        f.close();
    }
}

4、JDBC封装mysql数据库连接

 1 package com.aaa.demo;
 2 
 3 import java.io.FileNotFoundException;
 4 import java.io.FileReader;
 5 import java.sql.Connection;
 6 import java.sql.DriverManager;
 7 import java.util.Properties;
 8 
 9 //封装JDBC
10 public class SQLEns {
11     private  static Connection conn;
12     public static Connection jdbc_enc(String url, String user, String password){
13         try {
14             //注册驱动
15             Class.forName("com.mysql.jdbc.Driver");
16             //获得数据库连接对象
17             conn = DriverManager.getConnection(url, user, password);
18         } catch (Exception e) {
19         }
20         return conn;
21     }
22 }