SpringBoot: 基于MyBatis的多数据源配置

蔚落 2022-08-29 00:01 145阅读 0赞

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#### 前言 ####

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之前在使用SpringBoot搭建后台服务的过程中,一般都是访问一个数据库,一个数据源.这次在新的项目中由于使用的MQTT服务,需要进行鉴权操作,但是MQTT服务有多个项目使用,所以它的鉴权数据库在一个单独的数据库中,这时候我们就需要在SpringBoot配置多数据源.

整体来说是比较简单的,但是对于我这个小白也是折腾了一天多,现在也是很多原理没有搞懂,这里只能算是记录一下,方便以后的查找.

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#### 配置 application.yml ####

--------------------

首先要在 application.yml 中配置两个数据源,这里我就以我工程中为例,主库的数据源叫做main,mqtt数据库叫做mqtt,这里大家可以自定义,不过多叙述了.具体如下所示.

spring:
      datasource:
        main:
          url: jdbc:mysql://************************************
          username: root
          password: 123456
          driver-class-name: com.mysql.jdbc.Driver
        mqtt:
          url: jdbc:mysql://************************************
          username: root
          password: 123456
          driver-class-name: com.mysql.jdbc.Driver

#### 多数据源配置类 ####

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新增一个 DataSourceConfig 数据源配置类.具体代码如下所示.

/** * 数据库多数据源配置 */
    @Configuration
    public class DataSourceConfig { 
    
        // GreenRoom主数据库配置
        @Primary
        @Bean(name = "mainDataSourceProperties")
        @ConfigurationProperties(prefix = "spring.datasource.main")
        public DataSourceProperties mainDataSourceProperties() { 
            return new DataSourceProperties();
        }
    
        // GreenRoom主数据库 数据源
        @Primary
        @Bean(name = "mainDataSource")
        public DataSource mainDataSource(@Qualifier("mainDataSourceProperties") DataSourceProperties dataSourceProperties) { 
            return dataSourceProperties.initializeDataSourceBuilder().build();
        }
    
        // mqtt数据库数据源配置
        @Bean(name = "mqttDataSourceProperties")
        @ConfigurationProperties(prefix = "spring.datasource.mqtt")
        public DataSourceProperties mqttDataSourceProperties() { 
            return new DataSourceProperties();
        }
    
        // mqtt数据库数据源
        @Bean("mqttDataSource")
        public DataSource mqttDataSource(@Qualifier("mqttDataSourceProperties") DataSourceProperties dataSourceProperties) { 
            return dataSourceProperties.initializeDataSourceBuilder().build();
        }
    }

#### Main和Mqtt数据源配置类 ####

--------------------

上面已经把多数据源配置类设置完成了,接下来,我们就要Main和Mqtt数据源进行各自单独的配置了,单独配置的意义就在于让Main和Mqtt 去扫描自己的Dao.java和 Dao.xml.

首先我们先看一下,我的项目具体的目录结构,可能不太规范…大家见谅.

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接下来,我们就具体看一下main数据源的配置类,这里以我项目中的 **GreenRoomDataSourceConfig** 为例.

/** * 主数据库Mapper配置 */
    @Configuration
    @MapperScan(basePackages ="com.dong.gen.mapper", sqlSessionTemplateRef  = "mainSqlSessionTemplate")
    public class GreenRoomDataSourceConfig { 
    
        // 主数据源 main数据源
        @Primary
        @Bean("mainSqlSessionFactory")
        public SqlSessionFactory mainSqlSessionFactory(@Qualifier("mainDataSource") DataSource dataSource) throws Exception { 
            SqlSessionFactoryBean sqlSessionFactory = new SqlSessionFactoryBean();
            sqlSessionFactory.setDataSource(dataSource);
            sqlSessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver().
                    getResources("classpath*:com/dong/gen/mapper/**/*.xml"));
            return sqlSessionFactory.getObject();
        }
    
        @Primary
        @Bean(name = "mainTransactionManager")
        public DataSourceTransactionManager mainTransactionManager(@Qualifier("mainDataSource") DataSource dataSource) { 
            return new DataSourceTransactionManager(dataSource);
        }
    
        @Primary
        @Bean(name = "mainSqlSessionTemplate")
        public SqlSessionTemplate mainSqlSessionTemplate(@Qualifier("mainSqlSessionFactory") SqlSessionFactory sqlSessionFactory) { 
            return new SqlSessionTemplate(sqlSessionFactory);
        }
    }

然后再看一下 **MqttDataSourceConfig** 这个配置类.

/** * MQTT数据库Mapper配置 */
    @Configuration
    @MapperScan(basePackages ="com.dong.mqtt.mapper", sqlSessionTemplateRef  = "mqttSqlSessionTemplate")
    public class MqttDataSourceConfig { 
        // MQTT数据源
        @Bean("mqttSqlSessionFactory")
        public SqlSessionFactory mqttSqlSessionFactory(@Qualifier("mqttDataSource") DataSource dataSource) throws Exception { 
            SqlSessionFactoryBean sqlSessionFactory = new SqlSessionFactoryBean();
            sqlSessionFactory.setDataSource(dataSource);
            sqlSessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver().
                    getResources("classpath*:com/dong/mqtt/mapper/*.xml"));
            return sqlSessionFactory.getObject();
        }
    
        @Bean(name = "mqttTransactionManager")
        public DataSourceTransactionManager mqttTransactionManager(@Qualifier("mqttDataSource") DataSource dataSource) { 
            return new DataSourceTransactionManager(dataSource);
        }
    
        @Bean(name = "mqttSqlSessionTemplate")
        public SqlSessionTemplate mqttSqlSessionTemplate(@Qualifier("mqttSqlSessionFactory") SqlSessionFactory sqlSessionFactory) { 
            return new SqlSessionTemplate(sqlSessionFactory);
        }
    }

这两个文件的核心是扫包的配置代码,具体如下所示.

@MapperScan(basePackages ="com.dong.gen.mapper", sqlSessionTemplateRef  = "mainSqlSessionTemplate")
    
    sqlSessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver().
                    getResources("classpath*:com/dong/gen/mapper/**/*.xml"));

@MapperScan(basePackages ="com.dong.mqtt.mapper", sqlSessionTemplateRef  = "mqttSqlSessionTemplate")
    
    sqlSessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver().
                    getResources("classpath*:com/dong/mqtt/mapper/*.xml"));

#### 结语 ####

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到此,SpringBoot + MyBatis 多数据源配置就算完成了,如果有任何问题,欢迎评论,谢谢.

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[f3ec44e647a9575dfdc9b5a45a6bb3d2.png]: /images/20220829/4eb934febec64276aa58077fa1d288b4.png
[32a5a1d0ab9aacf66bdac14e8f8cac0c.png]: /images/20220829/93ce96eebe374af6b3f4ee6928c7835f.png
[5fa75a89d61e1b09b61d27fe33e4b993.gif]: /images/20220829/35c09521d03a4e958809c8a1a074284e.png