一、JDBC配置类

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.sql.*;
import java.util.Properties;public class Config {private static String username;private static String password;private static String url;private static String driverClass;static{Properties prop = new Properties();try {//读取配置文件InputStream in = new FileInputStream("JavaDemo10/config/jdbc.properties");//加载配置文件内容prop.load(in);// acquire the properties from fileusername = prop.getProperty("username");password = prop.getProperty("password");url = prop.getProperty("url");driverClass = prop.getProperty("driverClass");// register the driverif(driverClass != null && url != null && username != null && password != null){//加载驱动Class.forName(driverClass);}} catch (FileNotFoundException e) {throw new RuntimeException(e);} catch (IOException e) {throw new RuntimeException(e);} catch (ClassNotFoundException e) {throw new RuntimeException(e);}}/*** @description:  获取连接* @param* @return: java.sql.Connection*/public static Connection getConnection() throws SQLException {Connection con = null;try{con = DriverManager.getConnection(url,username,password);}catch (Exception e){e.printStackTrace();}return con;}/*** @description:  释放资源* @param con* @param stat* @param res*/public static void close(Connection con, Statement stat , ResultSet res) throws SQLException {if(con != null){con.close();}if (stat != null) {stat.close();}if (res != null) {res.close();}}
}

二、配置文件

#mysql8驱动
driverClass = com.mysql.cj.jdbc.Driver
#用户名
username = root
#数据库密码
password = 123456
#数据库url
url = jdbc:mysql://localhost:3306/databaseName

三、通用工具类

import java.sql.*;/*** @Description: jdbc封装工具类* @Version: 1.0*/
public class JdbcUtils {private static Connection con = null;private static Statement st = null;private static ResultSet rs = null;private static PreparedStatement ps = null;/*** @description: 通用更新封装* @param sql    sql语句* @param params   传入多参，也可以以数组形式传入* @return: java.sql.ResultSet*/public static int update(String sql,Object ...params) throws SQLException {int flag = 0;try {con = Config.getConnection();ps = con.prepareStatement(sql);for (int i = 0; i < params.length; i++) {ps.setObject(i+1,params[i]);}flag = ps.executeUpdate();} catch (SQLException e) {e.printStackTrace();}finally {Config.close(con,ps,null);}return flag;}/*** @description:  通用查询* @param sql* @param params* @return: java.sql.ResultSet*/public static ResultSet query(String sql,Object ...params) throws SQLException {try {con = Config.getConnection();ps = con.prepareStatement(sql);for (int i = 0; i < params.length; i++) {ps.setObject(i + 1, params[i]);}rs = ps.executeQuery();} catch (Exception e) {e.printStackTrace();}return rs;}
}