SpringBoot + Mybatis-Plus实现多数据源

标题最近工作的时候遇到里一种特殊情况，需要在一个项目中去查询两个不同的数据库，于是去研究了一下双数据源的使用

我们这里用db1和db2来简单区分两个数据源

spring:
  datasource:
    db1:
      driver-class-name: com.mysql.cj.jdbc.Driver
      jdbcUrl: jdbc:mysql://ip:port/数据库名称?serverTimezone=GMT%2b8&useUnicode=true&characterEncoding=UTF-8&useSSL=false&allowMultiQueries=true
      username: 
      password: 
    db2:
      driver-class-name: com.mysql.cj.jdbc.Driver
      jdbcUrl: jdbc:mysql://ip:port/数据库名称?serverTimezone=GMT%2b8&useUnicode=true&characterEncoding=UTF-8&useSSL=false&allowMultiQueries=true
      username: 
      password: 
server:
  port: 8081

包结构如下

Db1Config

package com.wjn.doubledatasource.config;

import com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean;
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.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.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;

@Configuration
@MapperScan(
		//指定扫描的包
		basePackages = "com.wjn.doubledatasource.db1.mapper",
        //指定这些包下的类使用的数据库会话工厂
        sqlSessionFactoryRef = "db1SqlSessionFactory")
public class Db1Config {

    /**
     * 自定义数据源配置信息
     * 注解@Primary表示该数据源作为默认数据源
     * 注解@ConfigurationProperties(prefix = "spring.datasource.db1")对应配置文件中配置的数据源连接信息
     * 方法名作为数据源bean的名称，可使用@Qualifier("")注解引用使用
     * @return
     */
    @Bean
    @Primary
    @ConfigurationProperties(prefix = "spring.datasource.db1")
    public DataSource db1DataSource() {
        return DataSourceBuilder.create().build();
    }


    /**
     * 返回data1数据库的会话工厂
     * @param dataSource
     * @return
     * @throws Exception
     **/
    @Bean
    @Primary
    public SqlSessionFactory db1SqlSessionFactory(@Qualifier("db1DataSource") DataSource dataSource) throws Exception {
        MybatisSqlSessionFactoryBean bean = new MybatisSqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        //扫描mapper文件，我这里为了简单，没有用mapper文件
//		bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("com.wjn.doubledatasource.db1.mapper.*"));
        return bean.getObject();
    }

    /** 返回data1数据库的会话模板
     * @param sessionFactory
     * @return
     * @throws Exception
     **/
    @Bean(name = "data1SqlSessionTemplate")
    public SqlSessionTemplate sqlSessionTemplate(@Qualifier("db1SqlSessionFactory") SqlSessionFactory sessionFactory) throws  Exception{
        return  new SqlSessionTemplate(sessionFactory);
    }

    /** 返回data1数据库的事务
     * @param dataSource
     * @return
     **/
    @Bean(name = "data1TransactionManager")
    public DataSourceTransactionManager transactionManager(@Qualifier("db1DataSource") DataSource dataSource){
        return new DataSourceTransactionManager(dataSource);
    }
}

Db2Config

package com.wjn.doubledatasource.config;

import com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean;
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.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.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;

@Configuration
@MapperScan(basePackages = "com.wjn.doubledatasource.db2.mapper",
        sqlSessionFactoryRef = "db2SqlSessionFactory")
public class Db2Config {
    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.db2")
    public DataSource db2DataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean
    public SqlSessionFactory db2SqlSessionFactory(@Qualifier("db2DataSource") DataSource dataSource) throws Exception {
        MybatisSqlSessionFactoryBean bean = new MybatisSqlSessionFactoryBean();
        bean.setDataSource(dataSource);
//		bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("com.wjn.doubledatasource.db2.mapper.*"));
        return bean.getObject();
    }

    @Bean(name = "data1SqlSessionTemplate")
    public SqlSessionTemplate sqlSessionTemplate(@Qualifier("db1SqlSessionFactory") SqlSessionFactory sessionFactory) throws  Exception{
        return  new SqlSessionTemplate(sessionFactory);
    }

    @Bean(name = "data1TransactionManager")
    public DataSourceTransactionManager transactionManager(@Qualifier("db1DataSource") DataSource dataSource){
        return new DataSourceTransactionManager(dataSource);
    }
}

controller、service、mapper照常写就可以，db1包下的会去访问第一个数据源，db2下的会去访问第二个数据源