关于spring-boot结合mybatis相关问题

1.新建spring-boot工程

2.加入相应jar包引用

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
   <groupId>org.mybatis.spring.boot</groupId>
   <artifactId>mybatis-spring-boot-starter</artifactId>
   <version>1.3.1</version>
</dependency>

<dependency>
   <groupId>mysql</groupId>
   <artifactId>mysql-connector-java</artifactId>
   <scope>runtime</scope>
</dependency>

3.配置数据源

spring.datasource.url=jdbc:mysql://*.*.*.*:3306/cloud?useUnicode=true&characterEncoding=UTF-8&useSSL=true
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.username=root
spring.datasource.password=root

4.在application.properties或bootstrap.properties中加入mybatis配置

mybatis.config-location=classpath:mybatis-config.xml
mybatis.mapper-locations=classpath:mappers/*.xml

5.在resource目录下新建mybatis-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD SQL Map Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <!--<mappers>
        <mapper resource="mapper/test-sqlMap.xml" />
    </mappers>-->
</configuration>

6.在resource目录下新建mappers文件夹，并新建文件test-sqlMap.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.cloud.mapper.TestMapper">
    <select id="queryUser" parameterType="java.util.Map" resultType="com.cloud.domain.TestVO">
        SELECT
        id as id  ,
        name as name  ,
        mail as mail  ,
        address as address
        from T_USER
        WHERE 1 = 1
        <if test="name != null and name != ''">
            AND name = #{name}
        </if>
        <if test="address != null and address != ''">
            AND address = #{address}
        </if>

    </select>

</mapper>

7.在spring-boot启动文件上加入@MapperScan("com.cloud.mapper")将所有的mapper接口加入mybatis

@EnableEurekaClient
@MapperScan("com.cloud.mapper")
@SpringBootApplication
public class ServiceCommonApplication {

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

8.新建接口TestMapper

public interface TestMapper  {

    public TestVO queryUser(Map<String,Object> paramMap);

}

9.新建VO类

public class TestVO {

    private Integer id;

    private String name;

    private String mail;

    private String address;
}

10.测试类

@Autowired
private TestMapper testMapper;

@GetMapping("testSql")
public String findUser(String name){
    Map<String,Object> paramMap = new HashMap<>();
    paramMap.put("name",name);
    TestVO user = testMapper.queryUser(paramMap);
    if (user == null) return "-9999";
    return JSON.toJSONString(user);
}

总结：采用以上方式基本可以将spring-boot与mybatis结合起来。回头再看一下test-sqlMap.xml配置文件。发现比较麻烦，首先每一个mapper配置文件中只能有一个namespace，这意味着，每一个mapper配置文件中只能存放一个与VO对象相匹配的CRUD相关操作。这与JPA操作时，每一个 Repository接口都与Entity实体相对应类似，基本都用于采用单表操作。对于多表操作缺乏灵活性。