jdbc-------JDBCUtil类 工具类

jdbcutil 主要处理的是 连接数据库， 和关闭各个流

 

1， 数据库连接的配置信息： mysql.properties (在工程的目录下)个人配置

url=jdbc:mysql://localhost:3306/test
driver=com.mysql.jdbc.Driver
username=root
password=123

2， 获取连接

读取配置信息，加载驱动。连接。（这个在后面的例子常用到）

package com.ljs.util;

import java.io.File;
import java.io.FileInputStream;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Properties;

public class JDBCUtil {private static String url;private static String user;private static String password;private static String driver;static{try {Properties properties = new Properties();FileInputStream fis = new FileInputStream(new File("mysql.properties"));properties.load(fis);url = properties.getProperty("url");user = properties.getProperty("username");password = properties.getProperty("password");driver = properties.getProperty("driver");Class.forName(driver);} catch (Exception e) {e.getMessage();}}public static Connection getConn() throws Exception{Connection connection = DriverManager.getConnection(url, user, password);return connection;}public static void close(ResultSet resultSet, PreparedStatement preparedStatement, Connection connection){try {if (resultSet != null) {resultSet.close();}if(preparedStatement != null ){preparedStatement.close();}if(connection != null ){connection.close();}} catch (SQLException e) {throw new RuntimeException();}}}