springboot + mybatis 项目中配置多个数据源

转载自http://blog.csdn.net/tracker_w/article/details/61202084

应用场景

项目需要同时连接两个不同的数据库A, B，并且它们都为主从架构，一台写库，多台读库。

多数据源

首先要将spring boot自带的DataSourceAutoConfiguration禁掉，因为它会读取application.properties文件的spring.datasource.*属性并自动配置单数据源。在@SpringBootApplication注解中添加exclude属性即可：

@SpringBootApplication(exclude = {
        DataSourceAutoConfiguration.class
})
public class TitanWebApplication {
    public static void main(String[] args) {
        SpringApplication.run(TitanWebApplication.class, args);
    }
}

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然后在application.properties中配置多数据源连接信息：

# titan库
spring.datasource.titan-master.url=jdbc:mysql://X.X.X.X:port/titan?characterEncoding=UTF-8
spring.datasource.titan-master.username=
spring.datasource.titan-master.password=
spring.datasource.titan-master.driver-class-name=com.mysql.jdbc.Driver
# 连接池配置
# 省略

# 其它库
spring.datasource.db2.url=jdbc:mysql://X.X.X.X:port/titan2?characterEncoding=UTF-8
spring.datasource.db2.username=
spring.datasource.db2.password=
spring.datasource.db2.driver-class-name=com.mysql.jdbc.Driver

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由于我们禁掉了自动数据源配置，因些下一步就需要手动将这些数据源创建出来：

@Configuration
public class DataSourceConfig {

    @Bean(name = "titanMasterDS")    @primary
    @ConfigurationProperties(prefix = "spring.datasource.titan-master") // application.properteis中对应属性的前缀
    public DataSource dataSource1() {
        return DataSourceBuilder.create().build();
    }




    @Bean(name = "ds2")
    @ConfigurationProperties(prefix = "spring.datasource.db2") // application.properteis中对应属性的前缀
    public DataSource dataSource2() {
        return DataSourceBuilder.create().build();
    }

}

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接下来需要配置两个mybatis的SqlSessionFactory分别使用不同的数据源：

@Configuration
@MapperScan(basePackages = {"titan.mapper"}, sqlSessionFactoryRef = "sqlSessionFactory1")
public class MybatisDbAConfig {

    @Autowired    @Qualifier("titanMasterDS")
    private DataSource ds1;


    @Bean    @primary
    public SqlSessionFactory sqlSessionFactory1() throws Exception {
        SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
        factoryBean.setDataSource(ds1); // 使用titan数据源, 连接titan库

        return factoryBean.getObject();

    }

    @Bean    @primary
    public SqlSessionTemplate sqlSessionTemplate1() throws Exception {
        SqlSessionTemplate template = new SqlSessionTemplate(sqlSessionFactory1()); // 使用上面配置的Factory
        return template;
    }
}

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经过上面的配置后，titan.mapper下的Mapper接口，都会使用titan数据源。同理可配第二个SqlSessionFactory:

@Configuration
@MapperScan(basePackages = {"other.mapper"}, sqlSessionFactoryRef = "sqlSessionFactory2")
public class MybatisDbBConfig {
    @Autowired
    @Qualifier("ds2")
    private DataSource ds2;

    @Bean
    public SqlSessionFactory sqlSessionFactory2() throws Exception {
        SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
        factoryBean.setDataSource(ds2);


        return factoryBean.getObject();

    }

    @Bean
    public SqlSessionTemplate sqlSessionTemplate2() throws Exception {
        SqlSessionTemplate template = new SqlSessionTemplate(sqlSessionFactory2());
        return template;
    }
}

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完成这些配置后，假设有2个Mapper titan.mapper.UserMapper和other.mapper.RoleMapper，使用前者时会自动连接titan库，后者连接ds2库。