Spring Boot多数据源配置之Mybatis

  • 前言
  • 创建工程
  • 多数据源配置
  • Mybatis配置
  • Mapper
  • 测试

前言

  关于多数据源的配置,前面介绍过JdbcTemplate多数据源配置,那个比较简单,本文来说说MyBatis多数据源的配置。其实关于多数据源,复杂的就直接上分布式数据库中间件,简单的再考虑多数据源。这是项目中的建议,技术上的话,当然还是各种技术都要掌握的。

创建工程

  还是跟前文一样创建Spring Boot项目,导入web、Mybatis、MySQL依赖。项目创建完成后,添加Druid依赖,和JdbcTemplate一样,这里添加Druid依赖也必须是专为Spring boot打造的Druid,不能使用传统的Druid。完整的依赖如下:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.7.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.yjn</groupId>
    <artifactId>mybatis</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>mybatis</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.0</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.10</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

多数据源配置

接下来配置多数据源,这里基本上还是和JdbcTemplate多数据源的配置方式一致,首先在application.properties中配置数据库基本信息,然后提供两个DataSource即可,这里我再把代码贴出来,里边的道理条条框框的,大伙可以参考前面的文章,这里不再赘述。

application.properties中的配置:

spring.datasource.one.url=jdbc:mysql:///test01?useUnicode=true&characterEncoding=utf-8
spring.datasource.one.username=root
spring.datasource.one.password=root
spring.datasource.one.type=com.alibaba.druid.pool.DruidDataSource

spring.datasource.two.url=jdbc:mysql:///test02?useUnicode=true&characterEncoding=utf-8
spring.datasource.two.username=root
spring.datasource.two.password=root
spring.datasource.two.type=com.alibaba.druid.pool.DruidDataSource

然后再提供两个DataSource,如下:

@Configuration
public class DataSourceConfig {
    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.one")
    DataSource dsOne() {
        return DruidDataSourceBuilder.create().build();
    }
    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.two")
    DataSource dsTwo() {
        return DruidDataSourceBuilder.create().build();
    }
}

Mybatis配置

接下来则是MyBatis的配置,不同于JdbcTemplate,MyBatis的配置要稍微麻烦一些,因为要提供两个Bean,因此这里两个数据源我将在两个类中分开来配置,首先来看第一个数据源的配置:

@Configuration
@MapperScan(basePackages = "com.yjn.mybatis.mapper",sqlSessionFactoryRef = "sqlSessionFactory1",sqlSessionTemplateRef = "sqlSessionTemplate1")
public class MyBatisConfigOne {
    @Resource(name = "dsOne")
    DataSource dsOne;

    @Bean
    SqlSessionFactory sqlSessionFactory1() {
        SqlSessionFactory sessionFactory = null;
        try {
            SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
            bean.setDataSource(dsOne);
            sessionFactory = bean.getObject();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return sessionFactory;
    }
    @Bean
    SqlSessionTemplate sqlSessionTemplate1() {
        return new SqlSessionTemplate(sqlSessionFactory1());
    }
}

创建MyBatisConfigOne类,首先指明该类是一个配置类,配置类中要扫描的包是org.sang.mybatis.mapper,即该包下的Mapper接口将操作dsOne中的数据,对应的SqlSessionFactory和SqlSessionTemplate分别是sqlSessionFactory1和sqlSessionTemplate1,在MyBatisConfigOne内部,分别提供SqlSessionFactory和SqlSessionTemplate即可,SqlSessionFactory根据dsOne创建,然后再根据创建好的SqlSessionFactory创建一个SqlSessionTemplate。

这里配置完成后,依据这个配置,再来配置第二个数据源即可:

@Configuration
@MapperScan(basePackages = "com.yjn.mybatis.mapper2",sqlSessionFactoryRef = "sqlSessionFactory2",sqlSessionTemplateRef = "sqlSessionTemplate2")
public class MyBatisConfigTwo {
    @Resource(name = "dsTwo")
    DataSource dsTwo;

    @Bean
    SqlSessionFactory sqlSessionFactory2() {
        SqlSessionFactory sessionFactory = null;
        try {
            SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
            bean.setDataSource(dsTwo);
            sessionFactory = bean.getObject();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return sessionFactory;
    }
    @Bean
    SqlSessionTemplate sqlSessionTemplate2() {
        return new SqlSessionTemplate(sqlSessionFactory2());
    }
}

好了,这样MyBatis多数据源基本上就配置好了,接下来只需要在com.yjn.mybatis.mapper和com.yjn.mybatis.mapper2包中提供不同的Mapper,Service中注入不同的Mapper就可以操作不同的数据源。

Mapper

com.yjn.mybatis.mapper中的mapper:

public interface UserMapper {
    List<User> getAllUser();
}

对应的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.yjn.mybatis.mapper.UserMapper">
    <select id="getAllUser" resultType="com.yjn.mybatis.bean.User">
        select * from t_user;
    </select>
</mapper>

org.sang.mybatis.mapper2中的mapper:

public interface UserMapper2 {
    List<User> getAllUser();
}

对应的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.yjn.mybatis.mapper2.UserMapper2">
    <select id="getAllUser" resultType="com.yjn.mybatis.bean.User">
        select * from t_user;
    </select>
</mapper>

配置mapper路径

<resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                </includes>
            </resource>
            <resource>
                <directory>src/main/resources</directory>
            </resource>
        </resources>

测试

@RunWith(SpringRunner.class)
@SpringBootTest
public class MybatisApplicationTests {

    @Autowired
    UserMapper userMapper;
    @Autowired
    UserMapper2 userMapper2;

    @Test
    public void contextLoads() {
        List<User> list = userMapper.getAllUsers();
        System.out.println(list);
        list = userMapper2.getAllUsers();
        System.out.println(list);
    }

}

SpringBoot mybatispuls 多数据源_Mybatis