java 连接MySql的三种方法

[java]代码库

import java.sql.Connection;   
import java.sql.DriverManager;   
import java.util.Properties;   
 
//java 连接MySql的三种方法
public class ConnectionUtil { 
   
        //第一种方法   
        public Connection getConnection(){   
                Connection conn = null;   
                try {   
                        //Class.forName加载驱动   
                        Class.forName("com.mysql.jdbc.Driver");   
                        //DriverManager获得连接   
                        conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/jdbc_db","root","mysqladmin");   
                        return conn;   
                } catch (Exception e) {   
                        e.printStackTrace();   
                }   
                return null;   
        }  
 
  
        //第二种方法   
        public Connection getConnection(String driver,String url,String user,String password){   
                Connection conn = null;   
                try {   
                        //Class.forName加载驱动   
                        Class.forName(driver);   
                        //DriverManager获得连接   
                        conn = DriverManager.getConnection(url,user,password);   
                        return conn;   
                } catch (Exception e) {   
                        e.printStackTrace();   
                }   
                return null;   
        }   
 
 
        //第三种方法   
        public Connection openConnection(){   
                String driver = "";   
                String url = "";   
                String user = "";   
                String password = "";   
                Properties prop = new Properties();   
                Connection conn = null;   
                try {   
                        //加载属性文件   
                        prop.load(this.getClass().getClassLoader().getResourceAsStream("DBConfig.properties"));   
                        driver = prop.getProperty("driver");   
                        url = prop.getProperty("url");   
                        user = prop.getProperty("user");   
                        password = prop.getProperty("password");   
                        //Class.forName加载驱动   
                        Class.forName(driver);   
                        //DriverManager获得连接   
                        conn = DriverManager.getConnection(url,user,password);   
                        return conn;   
                } catch (Exception e) {   
                        e.printStackTrace();   
                }   
                return null;   
        }   
 
}