SpringBoot 2.0 | SpringBoot + MyBatis 配置多数据源

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在传统的单体架构中，一个系统对应一个数据库，但在一个分布式系统中，比如微服务，每一个服务对应一个数据库，由于业务的需求，有时需要在一个服务中访问多个数据库的数据，需要配置多数据源，以下是SpringBoot 2.0.5 + MyBatis + .yml 格式配置多数据源的方法。

数据源配置

application.yml 文件的配置

spring:
  datasource:
    article-service:
      driver-class-name: com.mysql.jdbc.Driver
      username: root
      password: roo
      jdbc-url: jdbc:mysql://localhost:3306/articleservice?useSSL=false&useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&autoReconnect=true

    video-service:
      driver-class-name: com.mysql.jdbc.Driver
      username: root
      password: roo
      jdbc-url: jdbc:mysql://localhost:3306/videoservice?useSSL=false&useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&autoReconnect=true

# 端口设置
server:
  port: 8083

在单数据源的配置中，数据库地址的写法是

url: jdbc:mysql://localhost:3306

多数据源中，需要在 url 前面加上 jdbc-

 jdbc-url: jdbc:mysql://localhost:3306

数据源的配置

创建多个配置类，每一个类对应一个数据源的配置，以下是一个数据源的配置。

@Configuration
//配置mbatis接口
@MapperScan(basePackages = "com.hly.springbootmybatismultidatasources.dao.ArticleService", sqlSessionFactoryRef = "articleServiceSqlSessionFactory")
public class ArticleServiceDataSourceConfig {

    //将对象放入容器中
    @Bean(name = "articleServiceDataSource")
    //表示默认数据源
    @Primary
    //yml配置的对象
    @ConfigurationProperties(prefix = "spring.datasource.article-service")
    public DataSource getArticleServiceDataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "articleServiceSqlSessionFactory")
    @Primary
    //@Qualifier 查找Spring 容器中名为articleServiceDataSource的对象
    public SqlSessionFactory articleServiceSqlSessionFactory(@Qualifier("articleServiceDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        //配置Mybatis XML文件的位置
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath*:mapper/articleService/*.xml"));
        return bean.getObject();
    }
    @Bean(name = "articleServiceSqlSessionTemplate")
    @Primary
    public SqlSessionTemplate articleServiceSqlSessionTemplate(@Qualifier("articleServiceSqlSessionFactory") SqlSessionFactory sqlSessionFactory){
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

Mapper & Dao

每一个数据源对应的 Mapper 和 Dao 以不同的目录区分

测试

数据库

DROP TABLE IF EXISTS `video`;
CREATE TABLE `video`(
  `v_id` int(11) NOT NULL AUTO_INCREMENT,
  `v_name` varchar(20) NOT NULL DEFAULT '',
  `a_id` int(11) NOT NULL,
  PRIMARY KEY (`v_id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8 DEFAULT CHARSET=utf8


DROP TABLE IF EXISTS `article`;
CREATE TABLE `article`(
  `a_id` int(11) NOT NULL AUTO_INCREMENT,
  `a_name` varchar(20) NOT NULL DEFAULT '',
  PRIMARY KEY (`a_id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8 DEFAULT CHARSET=utf8

Mapper.xml 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="com.hly.springbootmybatismultidatasources.dao.ArticleService.ArticleDao">

    <resultMap id="articleResult" type="com.hly.springbootmybatismultidatasources.entity.Article">
        <id column="a_id" property="a_id"/>
        <result column="a_name" property="a_name"/>
    </resultMap>

    <select id="getArticles" resultMap="articleResult">
        SELECT * FROM article;
    </select>
</mapper>

<?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.hly.springbootmybatismultidatasources.dao.VideoService.VideoDao">

    <resultMap id="videoResultMap" type="com.hly.springbootmybatismultidatasources.entity.Video">
        <id column="v_id" property="v_id"/>
        <result column="v_name" property="v_name"/>
        <result column="a_name" property="a_name"/>
    </resultMap>

    <select id="getVideoByArticleId" parameterType="integer" resultMap="videoResultMap">
        SELECT * FROM video
        <if test="a_id!=null">
            WHERE a_id = #{a_id}
        </if>
    </select>
</mapper>

Dao 接口

@Repository
public interface ArticleDao {
    List<Article> getArticles();
}

@Repository
public interface VideoDao {
    List<Video> getVideoByArticleId(@Param(value="a_id")int  a_id);
}

Controller

@RestController
public class TestController {

    @Autowired
    ArticleDao articleDao;

    @Autowired
    VideoDao videoDao;

    @RequestMapping(value = "/articles")
    public Object getArticle(){
        return articleDao.getArticles();
    }

    @RequestMapping(value = "/videos")
    public Object getVideoByArticleId(int a_id){
        return videoDao.getVideoByArticleId(a_id);
    }
}

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