springboot + mybatis-plus 分包实现多数据源配置

老马啸西风2020年6月21日大约 4 分钟

业务背景

同一个应用需要访问多个数据源，比如读写分离，或者需要对不同的库做 ETL 之类的。

那么如何配置多数据源呢？

文本就 mybatis 和 mybatis-plus 提供配置的基础案例。

实现方式

多数据源可以采用分包，或者通过 aop+注解的方式实现。

整体的配置

使用 springboot 做个案例。

maven 配置

对应的 maven 配置如下：



    4.0.0

    mp-sb-mluti

    
        org.springframework.boot
        spring-boot-starter-parent
        2.1.6.RELEASE
         
    

    
        3.4.4
        1.3.1
        2.3
        1.8
    

    
        
            org.springframework.boot
            spring-boot-starter-jdbc
        
        
        
            org.mybatis
            mybatis
            ${mybatis.version}
        
        
            org.mybatis
            mybatis-spring
            ${mybatis-spring.version}
        
        
            com.baomidou
            mybatis-plus
            ${mybatis-plus.version}
            
                
                    mybatis
                    org.mybatis
                
                
                    mybatis-spring
                    org.mybatis
                
            
        
        
            mysql
            mysql-connector-java
            runtime
        
        
            com.oracle
            ojdbc6
            11.2.0.3
        
        
        
            com.alibaba
            druid-spring-boot-starter
            1.1.14
        
        
            org.springframework.boot
            spring-boot-starter-test
            test
        
        
            org.springframework.boot
            spring-boot-starter-web
        
        
        
            org.apache.velocity
            velocity-engine-core
            2.0
        
        
            org.springframework.boot
            spring-boot-configuration-processor
            true

目录结构

├─java
│  └─dal
│      │  Application.java
│      │
│      ├─config
│      │      MainDataSourceConfig.java
│      │      SecondDataSourceConfig.java
│      │
│      ├─entity
│      │  ├─main
│      │  │      MainModel.java
│      │  │
│      │  └─second
│      │          SecondModel.java
│      │
│      ├─mapper
│      │  ├─main
│      │  │      MainMapper.java
│      │  │
│      │  └─second
│      │          SecondMapper.java
│      │
│      └─service
│          ├─main
│          │  │  MainService.java
│          │  │
│          │  └─impl
│          │          MainServiceImpl.java
│          │
│          └─second
│              │  SecondService.java
│              │
│              └─impl
│                      SecondServiceImpl.java
│
└─resources
    │  application.properties
    │
    └─dal.mapper
        │  README
        │
        ├─main
        │      MainMapper.xml
        │
        └─second
                SecondMapper.xml

main 方法

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.boot.autoconfigure.jdbc.DataSourceTransactionManagerAutoConfiguration;
import org.springframework.boot.context.properties.EnableConfigurationProperties;

@SpringBootApplication
@EnableConfigurationProperties
@EnableAutoConfiguration(exclude = {DataSourceAutoConfiguration.class, DataSourceTransactionManagerAutoConfiguration.class})
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

}

mybatis 配置单数据源

代码生成

generatorConfig.xml

对应的 mybatis-plus 数据源配置

MainDataSourceConfig.java

package dal.config;

import com.alibaba.druid.pool.DruidDataSource;
import com.baomidou.mybatisplus.plugins.PaginationInterceptor;
import com.baomidou.mybatisplus.spring.MybatisSqlSessionFactoryBean;
import org.apache.ibatis.plugin.Interceptor;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
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 javax.sql.DataSource;

@Configuration
@MapperScan(basePackages = "dal.mapper.main", sqlSessionFactoryRef = "mainSqlSessionFactory")
public class MainDataSourceConfig {

    @Bean("mainSqlSessionTemplate")
    public SqlSessionTemplate mainSqlSessionTemplate(
            @Qualifier("mainSqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }

    @Bean("mainSqlSessionFactory")
    @Primary
    public SqlSessionFactory sqlSessionFactory(@Qualifier("mainDataSource") DataSource dataSource,@Qualifier("mainPaginationInterceptor") PaginationInterceptor paginationInterceptor) throws Exception {
        MybatisSqlSessionFactoryBean sqlSessionFactoryBean = new MybatisSqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(dataSource);
        sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:dal/mapper/main/*.xml"));
        Interceptor[] plugins = new Interceptor[]{paginationInterceptor};
        sqlSessionFactoryBean.setPlugins(plugins);
        return sqlSessionFactoryBean.getObject();
    }

    @Bean("mainPaginationInterceptor")
    public PaginationInterceptor paginationInterceptor() {
        return new PaginationInterceptor();
    }

    @Bean("mainDataSource")
    public DataSource mainDataSource() {
        DruidDataSource druidDataSource = new DruidDataSource();
        druidDataSource.setDriverClassName("oracle.jdbc.driver.OracleDriver");
        druidDataSource.setUrl("jdbc:oracle:thin:@//ip:port/db");
        druidDataSource.setUsername("name");
        druidDataSource.setPassword("password");
        return druidDataSource;
    }

}

mybatis 的配置

二者最核心的区别就在于 sqlSessionFactory 方法，mybatis 直接使用 SqlSessionFactoryBean 替换掉 MybatisSqlSessionFactoryBean。

@Bean("mainSqlSessionFactory")
@Primary
public SqlSessionFactory sqlSessionFactory(@Qualifier("mainDataSource") DataSource dataSource,@Qualifier("mainPaginationInterceptor")PaginationInterceptor paginationInterceptor) throws Exception {
    SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
    sqlSessionFactoryBean.setDataSource(dataSource);
    sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:dal/mapper/main/*.xml"));
    Interceptor[] plugins = new Interceptor[]{paginationInterceptor};
    sqlSessionFactoryBean.setPlugins(plugins);
    return sqlSessionFactoryBean.getObject();
}

mybatis 配置多数据源-分包

其实如果使用分包的话，实现起来非常简单。

就是 entity/mapper/xml 都放在独立的包中，然后扫包的时候独立即可。

mybatis-plus 例子

package dal.config;

/**
 *
 * https://blog.csdn.net/qq_36134369/article/details/95036273
 *
 * @author binbin.hou
 * @since 1.0.0
 */

import com.alibaba.druid.pool.DruidDataSource;
import com.baomidou.mybatisplus.plugins.PaginationInterceptor;
import com.baomidou.mybatisplus.spring.MybatisSqlSessionFactoryBean;
import org.apache.ibatis.plugin.Interceptor;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
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 javax.sql.DataSource;

@Configuration
@MapperScan(basePackages = "dal.mapper.second", sqlSessionFactoryRef = "secondSqlSessionFactory")
public class SecondDataSourceConfig {

    @Bean("secondSqlSessionTemplate")
    public SqlSessionTemplate secondSqlSessionTemplate(
            @Qualifier("secondSqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }

    @Bean("secondSqlSessionFactory")
    @Primary
    public SqlSessionFactory sqlSessionFactory(@Qualifier("secondDataSource") DataSource dataSource,@Qualifier("secondPaginationInterceptor") PaginationInterceptor paginationInterceptor) throws Exception {
        MybatisSqlSessionFactoryBean sqlSessionFactoryBean = new MybatisSqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(dataSource);
        sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:dal/mapper/second/*.xml"));
        Interceptor[] plugins = new Interceptor[]{paginationInterceptor};
        sqlSessionFactoryBean.setPlugins(plugins);
        return sqlSessionFactoryBean.getObject();
    }
    @Bean("secondPaginationInterceptor")
    public PaginationInterceptor paginationInterceptor() {
        return new PaginationInterceptor();
    }

    @Bean("secondDataSource")
    public DataSource secondDataSource() {
        DruidDataSource druidDataSource = new DruidDataSource();
        druidDataSource.setDriverClassName("oracle.jdbc.driver.OracleDriver");
        druidDataSource.setUrl("jdbc:oracle:thin:@ip2:port2/db2");
        druidDataSource.setUsername("name");
        druidDataSource.setPassword("password");
        return druidDataSource;
    }

}

注意：所有的插件，mybatis 配置都做要彻底隔离。

我在测试过程中为了复用，一开始将分页插件，全局配置等设置为公用，后来发现会导致数据源的混乱。

参考资料

项目模板丨多数据源搭建 maven+spring-boot+druid+mybatis-plus+分页插件+分包

springboot mybatis plus多数据源轻松搞定（上）

Mybatis plus 配置多数据源

贡献者

binbin.hou