上一节我们简单阐述了springboot多数据源如何配置。在实际的业务场景中我们常常遇到A服务依赖于B服务jar包，A服务和B服务业务数据分别入自己的库中。为何要这么做呢？比如B服务是日志SDK，A服务集成B服务来实现记录日志的功能，但是日志库和业务库又不是一个库，这种场景要求B服务相对简单，如果B服务比较繁杂，可以使用InnerAPI来实现该功能。

如何实现

B服务 ocean-syslog

1. 服务配置 application-log.yml

spring:datasource:secondary:driver-class-name: com.mysql.cj.jdbc.Driverjdbc-url: jdbc:mysql://localhost:3306/db-log?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=true&serverTimezone=GMT%2B8&allowMultiQueries=trueusername: rootpassword: 123456

2. 配置数据源和SqlSessionFactory

package com.angel.ocean.config;import com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.annotation.MapperScan;
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.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import javax.sql.DataSource;@Configuration
@MapperScan(basePackages = "com.angel.ocean.log.mapper", sqlSessionFactoryRef = "secondarySqlSessionFactory")
public class SecondaryMyBatisConfig {@Bean(name = "secondaryDataSource")@ConfigurationProperties(prefix = "spring.datasource.secondary")public DataSource secondaryDataSource() {return DataSourceBuilder.create().build();}@Bean(name = "secondarySqlSessionFactory")public SqlSessionFactory secondarySqlSessionFactory(@Qualifier("secondaryDataSource") DataSource dataSource) throws Exception {MybatisSqlSessionFactoryBean sessionFactoryBean = new MybatisSqlSessionFactoryBean();sessionFactoryBean.setDataSource(dataSource);sessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/log/*.xml"));return sessionFactoryBean.getObject();}@Bean(name = "secondaryTransactionManager")public DataSourceTransactionManager secondaryTransactionManager(@Qualifier("secondaryDataSource") DataSource dataSource) {return new DataSourceTransactionManager(dataSource);}
}

3. B服务代码截图
   

A服务 ocean-syslog-demo

1. 服务配置 application.yml

server:port: 8000spring:datasource:primary:driver-class-name: com.mysql.cj.jdbc.Driverjdbc-url: jdbc:mysql://localhost:3306/db-ocean?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=true&serverTimezone=GMT%2B8&allowMultiQueries=trueusername: rootpassword: 123456config:import: classpath:application-log.yml

注意：

A服务不能直接使用B的配置文件（application-log.yml），需要在A服务的配置文件（application.yml）引入才可以，spring.config.import = classpath:application-log.yml.

2. 配置数据源和SqlSessionFactory

package com.angel.ocean.config;import com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.annotation.MapperScan;
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.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;import javax.sql.DataSource;@Configuration
@MapperScan(basePackages = "com.angel.ocean.mapper", sqlSessionFactoryRef = "primarySqlSessionFactory")
public class PrimaryMyBatisConfig {@Primary@Bean(name = "primaryDataSource")@ConfigurationProperties(prefix = "spring.datasource.primary")public DataSource primaryDataSource() {return DataSourceBuilder.create().build();}@Primary@Bean(name = "primarySqlSessionFactory")public SqlSessionFactory primarySqlSessionFactory(@Qualifier("primaryDataSource") DataSource dataSource) throws Exception {MybatisSqlSessionFactoryBean sessionFactoryBean = new MybatisSqlSessionFactoryBean();sessionFactoryBean.setDataSource(dataSource);sessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/*.xml"));return sessionFactoryBean.getObject();}@Primary@Bean(name = "primaryTransactionManager")public DataSourceTransactionManager primaryTransactionManager(@Qualifier("primaryDataSource") DataSource dataSource) {return new DataSourceTransactionManager(dataSource);}
}

3. 引入B服务

<dependency><groupId>com.angel.ocean</groupId><artifactId>ocean-syslog</artifactId><version>1.0.0</version>
</dependency>

4. A服务代码截图

5. 启动类

package com.angel.ocean;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.transaction.annotation.EnableTransactionManagement;@EnableTransactionManagement
@SpringBootApplication
public class Application {public static void main(String[] args) {SpringApplication.run(Application.class, args);}
}

运行截图：