<!-- mysql -->

        <dependency>

            <groupId>mysql</groupId>

            <artifactId>mysql-connector-java</artifactId>

            <version>5.1.31</version>

        </dependency>

package com.test;

import java.sql.*; 

public class jdbc {

	public static void main(String[] args) {

		//数据库连接

		Connection connection = null;

		//预编译的statement

		PreparedStatement preparedStatement = null;

		//结果集

		ResultSet resultSet = null;

		try{

			//加载数据库驱动

			Class.forName("com.mysql.jdbc.Driver");

			//通过驱动管理类获取数据库链接,用户名及密码

			connection = DriverManager.getConnection("jdbc:mysql://192.168.6.12:3306/test","dev","mybatis");

			//定义sql语句   ？表示占位符

			String sql = "select * from user where userName= ?";

			//获取预处理statement

			preparedStatement = connection.prepareStatement(sql);

			//设置参数，第一个参数为sql语句中参数的序号，第二个参数为设置的参数值

			preparedStatement.setString(1, "小明");

			//向数据库发出sql执行查询，查询出结果集

			resultSet = preparedStatement.executeQuery();

			//遍历结果集

			while(resultSet.next()){

				System.out.println(resultSet.getString("id")+"   "+resultSet.getString("username"));

			}

		}catch(Exception e){

			e.printStackTrace();

		}finally{

			//释放资源

			if(resultSet != null){

				try{

					resultSet.close();

				}catch(Exception e){

					e.printStackTrace();

				}

			}

		}

	}

}