springboot中mybatis多数据源实现

川长思鸟来 2022-02-05 02:09 249阅读 0赞

多种数据源的共同使用在日常开发中是很常见的，当然微服务中可能没那么常见，毕竟服务划分细致，数据源也就单独出去了。这里来看一下，在springboot中mybatis的多数据源实现（这里选择mysql为数据库）。

#### 多数据源配置 ####

mybatis和mysql在springboot中的引入这里就不在说了，不了解的可以参见[springboot中mysql与mybatis的引入][springboot_mysql_mybatis]。

多数据源，即为配置多个数据源，首先引入数据域配置（同时引入mybatis配置）：

datasource:
      master:
        type: com.alibaba.druid.pool.DruidDataSource
        jdbc-url: jdbc:mysql://127.0.0.1:3306/sbac_master?autoReconnect=true&useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&allowMultiQueries=true
        username: root
        password: 1234
        driver-class-name: com.mysql.cj.jdbc.Driver
      log:
        type: com.alibaba.druid.pool.DruidDataSource
        jdbc-url: jdbc:mysql://127.0.0.1:3306/sbac_log?autoReconnect=true&useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&allowMultiQueries=true
        username: root
        password: 1234
        driver-class-name: com.mysql.cj.jdbc.Driver
    
    mybatis:
      config-location: classpath:mybatis-config.xml
      mapper-locations: classpath:com/lazycece/sbac/mysql/data/dao/*/mapper/*.xml

springboot中，可以通过`@MapperScan`注解来实现多数据源中的数据源路由，可以选择使用注解的属性basePackages、basePackageClasses、annotationClass、markerInterface来标记mapper的所属数据源，注解的详情信息可自行参考源码。

这里使用包路径（basePackages，不适用其他属性表示该包下的所有mappe被包含）属性来示例配置两个数据源，当然也可以配置更多。下面给出以master和log命名数据源的配置：

package com.lazycece.sbac.mysql.multi2.config;
    
    import org.apache.ibatis.session.SqlSessionFactory;
    import org.mybatis.spring.SqlSessionFactoryBean;
    import org.mybatis.spring.SqlSessionTemplate;
    import org.mybatis.spring.annotation.MapperScan;
    import org.mybatis.spring.boot.autoconfigure.MybatisProperties;
    import org.springframework.beans.factory.annotation.Qualifier;
    import org.springframework.boot.context.properties.ConfigurationProperties;
    import org.springframework.boot.jdbc.DataSourceBuilder;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.context.annotation.Primary;
    import org.springframework.core.io.DefaultResourceLoader;
    import org.springframework.jdbc.datasource.DataSourceTransactionManager;
    
    import javax.annotation.Resource;
    import javax.sql.DataSource;
    
    @Configuration
    @MapperScan(basePackages = { "com.lazycece.sbac.mysql.data.dao.master"},
            sqlSessionFactoryRef = "masterSqlSessionFactory",
            sqlSessionTemplateRef = "masterSqlSessionTemplate")
    public class MasterDataSourceConfig { 
    
        @Resource
        private MybatisProperties mybatisProperties;
    
        @Primary
        @Bean(name = "masterDataSource")
        @ConfigurationProperties(prefix = "datasource.master")
        public DataSource masterDataSource() { 
            return DataSourceBuilder.create().build();
        }
    
        @Primary
        @Bean(name = "masterSqlSessionFactory")
        public SqlSessionFactory masterSqlSessionFactory(@Qualifier("masterDataSource") DataSource dataSource) throws Exception { 
            SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
            sqlSessionFactoryBean.setDataSource(dataSource);
            DefaultResourceLoader resourceLoader = new DefaultResourceLoader();
            sqlSessionFactoryBean.setConfigLocation(resourceLoader.getResource(mybatisProperties.getConfigLocation()));
            sqlSessionFactoryBean.setMapperLocations(mybatisProperties.resolveMapperLocations());
            return sqlSessionFactoryBean.getObject();
        }
    
        @Primary
        @Bean(name = "masterTransactionManager")
        public DataSourceTransactionManager masterTransactionManager(@Qualifier("masterDataSource") DataSource dataSource) { 
            return new DataSourceTransactionManager(dataSource);
        }
    
        @Primary
        @Bean(name = "masterSqlSessionTemplate")
        public SqlSessionTemplate masterSqlSessionTemplate(@Qualifier("masterSqlSessionFactory") SqlSessionFactory sqlSessionFactory) { 
            return new SqlSessionTemplate(sqlSessionFactory);
        }
    }

package com.lazycece.sbac.mysql.multi2.config;
    
    import org.apache.ibatis.session.SqlSessionFactory;
    import org.mybatis.spring.SqlSessionFactoryBean;
    import org.mybatis.spring.SqlSessionTemplate;
    import org.mybatis.spring.annotation.MapperScan;
    import org.mybatis.spring.boot.autoconfigure.MybatisProperties;
    import org.springframework.beans.factory.annotation.Qualifier;
    import org.springframework.boot.context.properties.ConfigurationProperties;
    import org.springframework.boot.jdbc.DataSourceBuilder;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.core.io.DefaultResourceLoader;
    import org.springframework.jdbc.datasource.DataSourceTransactionManager;
    
    import javax.annotation.Resource;
    import javax.sql.DataSource;
    
    @Configuration
    @MapperScan(basePackages = { "com.lazycece.sbac.mysql.data.dao.log"},
            sqlSessionFactoryRef = "logSqlSessionFactory",
            sqlSessionTemplateRef = "logSqlSessionTemplate")
    public class LogDataSourceConfig { 
    
        @Resource
        private MybatisProperties mybatisProperties;
    
        @Bean(name = "logDataSource")
        @ConfigurationProperties(prefix = "datasource.log")
        public DataSource logDataSource() { 
            return DataSourceBuilder.create().build();
        }
    
    
        @Bean(name = "logSqlSessionFactory")
        public SqlSessionFactory logSqlSessionFactory(@Qualifier("logDataSource") DataSource dataSource) throws Exception { 
            SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
            sqlSessionFactoryBean.setDataSource(dataSource);
            DefaultResourceLoader resourceLoader = new DefaultResourceLoader();
            sqlSessionFactoryBean.setConfigLocation(resourceLoader.getResource(mybatisProperties.getConfigLocation()));
            sqlSessionFactoryBean.setMapperLocations(mybatisProperties.resolveMapperLocations());
            return sqlSessionFactoryBean.getObject();
        }
    
        @Bean(name = "logTransactionManager")
        public DataSourceTransactionManager logTransactionManager(@Qualifier("logDataSource") DataSource dataSource) { 
            return new DataSourceTransactionManager(dataSource);
        }
    
        @Bean(name = "logSqlSessionTemplate")
        public SqlSessionTemplate logSqlSessionTemplate(@Qualifier("logSqlSessionFactory") SqlSessionFactory sqlSessionFactory) { 
            return new SqlSessionTemplate(sqlSessionFactory);
        }
    }

由于手动配置数据源，故可以在主函数禁用掉自动数据源配置`DataSourceAutoConfiguration`：

@SpringBootApplication(
            exclude = { DataSourceAutoConfiguration.class})
    public class SpringbootAcMysqlMulti2Application { 
    
        public static void main(String[] args) { 
            SpringApplication.run(SpringbootAcMysqlMulti2Application.class, args);
        }
    
    }

同样，手动配置数据源，mybatis的自动配置是可以被引入，但是不会生效。因为数据域手动配置，所以需要在配置中配置datasource的时候指定mybatis的属性配置信息。可以在上面的配置代码中看见，我们这里通过*MybatisProperties*方式加入的，因为mybatis的自动配置已经将信息注入到该类中，只需要利用其引入到自定义的datasource中即可：

DefaultResourceLoader resourceLoader = new DefaultResourceLoader();
    sqlSessionFactoryBean.setConfigLocation(resourceLoader.getResource(mybatisProperties.getConfigLocation()));
    sqlSessionFactoryBean.setMapperLocations(mybatisProperties.resolveMapperLocations());

#### 案例代码 ####

案例配置代码以及相应的演示代码地址如下：

[https://github.com/lazycece/springboot-actual-combat/tree/master/springboot-ac-mysql/springboot-ac-mysql-multi2][https_github.com_lazycece_springboot-actual-combat_tree_master_springboot-ac-mysql_springboot-ac-mysql-multi2]

[springboot_mysql_mybatis]: https://lazycece.github.io/2019/05/04/springboot%E4%B8%ADmysql%E4%B8%8Emybatis%E7%9A%84%E5%BC%95%E5%85%A5/
[https_github.com_lazycece_springboot-actual-combat_tree_master_springboot-ac-mysql_springboot-ac-mysql-multi2]: https://github.com/lazycece/springboot-actual-combat/tree/master/springboot-ac-mysql/springboot-ac-mysql-multi2