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

 1
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 }