Spring Boot整合Mybatis配置详解

首先，你得有个Spring Boot项目。

平时开发常用的repository包在mybatis里被替换成了mapper。

配置：

1.引入依赖：

<dependency>
　　<groupId>org.mybatis.spring.boot</groupId>
   <artifactId>mybatis-spring-boot-starter</artifactId>
   <version>1.1.1</version>
</dependency>

2.编辑 application.properties

spring.datasource.url=jdbc:mysql://localhost:3306/test?useSSL=true&serverTimezone=GMT
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

spring.servlet.multipart.max-request-size=2050MB
spring.servlet.multipart.max-file-size=2048MB

spring.jpa.hibernate.use-new-id-generator-mappings=false
server.port=8080
server.servlet.context-path=/mybatisDemo
spring.jmx.enabled=false

mybatis.type-aliases-package=tgc.edu.wx.entity
mybatis.mapperLocations=classpath:mapping/*.xml

这里要注意mybatis的两个相关配置，一是扫描的包，二是映射文件的地址。

3.建立构建web项目所需的类，以及在数据库建立实体类对应的表，完成后如下图：

PeopleMapper.java

package tgc.edu.wx.mapper;

import java.util.List;

import org.apache.ibatis.annotations.Mapper;

import tgc.edu.wx.entity.People;

@Mapper
public interface PeopleMapper {

    public List<People> findAll();
}

此文件注解为@Mapper而不再是@Repository。

PeopleService.java

package tgc.edu.wx.service;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import tgc.edu.wx.entity.People;
import tgc.edu.wx.mapper.PeopleMapper;

@Service
public class PeopleService {

    @Autowired
    private PeopleMapper peopleDAO;

    public List<People> findAll() {
     return    peopleDAO.findAll();
    }
}

PeopleController.java

package tgc.edu.wx.web.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;

import tgc.edu.wx.entity.People;
import tgc.edu.wx.service.PeopleService;

@Controller
@RequestMapping("/people")
public class PeopleController {

    @Autowired
    private PeopleService peopleService;

    @RequestMapping("/list")
    public String list(ModelMap map) {
         List<People> peoples = peopleService.findAll();
        map.put("peoples", peoples);
        return "peopleList";
    }
}

数据库：

4.依照 application.properties 中编写的地址在对应目录下创建xml格式的mybatis映射文件。

<?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="tgc.edu.wx.mapper.PeopleMapper">

<select id="findAll" resultType="tgc.edu.wx.entity.People">
SELECT * FROM people
</select>
</mapper>

其中<select>标签内的 id 对应的是dao层内的方法名，resultType对应的是查询返回结果集的类型，select内填写对应方法的语句即可。

5.最后，在启动类里加上注解用于给出需要扫描的mapper文件路径

package tgc.edu.wx;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@MapperScan("tgc.edu.wx.mapper")
public class MybatisDemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(MybatisDemoApplication.class, args);
    }

}

启动项目测试一下：

以上。