SpringBoot 整合Mybatis(xml版本)

操作数据的方式有很多框架，比如hibernate，mybatis，springboot data jpa等。
其中mybatis的xml版本可以做到灵活的书写sql，本文将基于springboot整合mybatis(xml版本)

1、引入依赖

<dependency>
     <groupId>org.mybatis.spring.boot</groupId>
     <artifactId>mybatis-spring-boot-starter</artifactId>
     <version>2.0.0</version>
 </dependency>
 <dependency>
     <groupId>mysql</groupId>
     <artifactId>mysql-connector-java</artifactId>
 </dependency>

2、配置application.yml

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/test?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=true
    username: root
    password: 123456
    driver-class-name: com.mysql.cj.jdbc.Driver

mybatis:
  config-location: classpath:mybatis/mybatis-config.xml
  mapper-locations: classpath:mybatis/mapper/**/*.xml
  type-aliases-package: com.example.springboottemplate.beans

mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
	<!--开启驼峰命名规则自动转换-->
	<settings>
		<setting name="mapUnderscoreToCamelCase" value="true" />
	</settings>
	<typeAliases>
		<typeAlias alias="Integer" type="java.lang.Integer" />
		<typeAlias alias="Long" type="java.lang.Long" />
		<typeAlias alias="HashMap" type="java.util.HashMap" />
		<typeAlias alias="LinkedHashMap" type="java.util.LinkedHashMap" />
		<typeAlias alias="ArrayList" type="java.util.ArrayList" />
		<typeAlias alias="LinkedList" type="java.util.LinkedList" />
	</typeAliases>
</configuration>

3、添加@MapperScan到启动类

添加mapper的dao层文件扫描，这样就不用每个dao文件都加@Mapper了

@SpringBootApplication
@MapperScan("com.example.springboottemplate.dao")
public class SpringbootTemplateApplication {

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

}

4、编写实体类UserDO

package com.example.springboottemplate.beans;

import lombok.Data;

import java.util.Date;

@Data
public class UserDO {
    private Long id;
    private String loginName;
    private String password;
    private String nickName;
    private Integer age;
    private Date createTime;
}

这里用到的 @Data 注解可以帮我们省略写getter/setter/toString，需要引入这个依赖才能使用

 <!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.10</version>
        </dependency>

5、Dao 层接口

public interface UserDao {
    UserDO selectById(Long id);
}

6、dao文件的xml

<?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.example.springboottemplate.dao.UserDao" >
    <select id="selectById" parameterType="long" resultType="UserDO">
        select * from sys_user
        where id = #{id}
    </select>
</mapper>

7、controller

@Controller
@RequestMapping("/sys/user")
public class UserController {
    @Autowired
    private UserDao userDao;

    @RequestMapping("/findOne")
    @ResponseBody
    public UserDO findUser(Long id) {
        return userDao.selectById(id);
    }
}

7、测试

我先预置一条数据到表中

源代码下载： 待传