MyBatis多数据源

添加依赖

<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>2.0.0</version>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.1.10</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.28</version>
    <scope>runtime</scope>
</dependency>

多数据源配置

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 = "org.sang.mybatis.mapper1",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.mapper1，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 = "org.sang.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org.sang.mybatis.mapper1和org.sang.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创建

org.sang.mybatis.mapper1中的mapper：

public interface UserMapperOne {
    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="org.sang.mybatis.mapper1.UserMapperOne">
    <select id="getAllUser" resultType="org.sang.mybatis.model.User">
        select * from t_user;
    </select>
</mapper>

org.sang.mybatis.mapper2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="org.sang.mybatis.mapper2.UserMapper">
    <select id="getAllUser" resultType="org.sang.mybatis.model.User">
        select * from t_user;
    </select>
</mapper>