Springboot连接mysql的几种方式

1：jdbc连接（不是用配置文件）

package com.springboot.first.jdbcUtil;

import org.springframework.beans.factory.annotation.Value;

import java.sql.*;

public class JdbcUtil { private static String DRIVER = “com.mysql.jdbc.Driver”; private static String USERNAME = “root”; private static String PASSWORD = “1234”; private static String URL = “jdbc:mysql://localhost:3306/USER”; private static Connection connection ;

/** * * Describe:获得数据库的连接 * @Author: wwh * @Date: 2018/10/29 13:05 * @Param: [] * @Return: java.sql.Connection */ public static Connection getConnection(){ try { Class.forName(DRIVER); connection = DriverManager.getConnection(URL,USERNAME,PASSWORD); } catch (Exception e) { e.printStackTrace(); } return connection; } /** * * Describe:关闭数据库操作 * @Author: wwh * @Date: 2018/10/29 13:06 * @Param: [connection, preparedStatement, resultSet] * @Return: void */ public static void close(Connection connection, PreparedStatement preparedStatement, ResultSet resultSet){ if(resultSet != null){ try { resultSet.close(); } catch (SQLException e) { e.printStackTrace(); } } if(preparedStatement != null ){ try { preparedStatement.close(); } catch (SQLException e) { e.printStackTrace(); } } if(connection != null){ try { connection.close(); } catch (SQLException e) { e.printStackTrace(); } } }

}

2：使用JdbcTemplate

1.application.yml配置如下 2.Controller代码 package com.springboot.first.controller;

import org.springframework.beans.factory.annotation.Autowired; import org.springframework.jdbc.core.JdbcTemplate; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController;

import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.Set;

@RestController @RequestMapping("/mydb") public class JdbcTemplateCintroller {

@Autowired private JdbcTemplate jdbcTemplate; @RequestMapping("/getUsers") public List<Map<String,Object>> getDbType(){ String sql = "SELECT * FROM USER"; List<Map<String,Object>> list = jdbcTemplate.queryForList(sql); for(Map<String,Object> map : list){ Set<Map.Entry<String, Object>> entries = map.entrySet( ); if(entries != null) { Iterator<Map.Entry<String, Object>> iterator = entries.iterator( ); while(iterator.hasNext( )) { Map.Entry<String, Object> entry = iterator.next( ); Object key = entry.getKey( ); Object value = entry.getValue(); System.out.println(key+":"+value); } } } return list; } }

3：SpringBoot+MyBatis

yml配置文件 mapper文件存放在resources文件夹下的mapper文件夹下。这里是通过yml配置文件中指定了mapper的存放位置。springboot自动加载

<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <mapper namespace="com.wwh.demo.storeBase.assistant.dao.AssistantDao"> <select id="queryObject" resultType="com.wwh.demo.storeBase.assistant.entity.Assistant" parameterType="string"> select * from assistant where assistant_name = #{assistantName} </select>

id：对应着AssistantDao中的方法名称 resultType：返回类型 parameterType：传入的参数类型

public interface AssistantDao { Assistant queryObject(String assistantName); } public interface AssistantService { Assistant queryAssistant(String assistantName); } @Service public class AssistantServiceImpl implements AssistantService { @Autowired private AssistantDao assistantDao; @Override public Assistant queryAssistant(String assistantName) { return assistantDao.queryObject(assistantName); } }

最后controller中注入一下AssistantService，然后调用方法就可以了

Assistant assistant = assistantService.queryAssistant(assistantName);

Mybatis