springboot配置多个数据源

序言

业务场景复杂时，可能会用到多个数据源，多数据源可以理解为多数据库，甚至可以是多个不同类型的数据库，比如一个是MySql，一个是Oracle，原理是相同的。

多数据源配置

1、配置多数据库

在springboot配置文件中填写数据库连接参数

spring:
  datasource:
    db1:
      driver-class-name: com.mysql.cj.jdbc.Driver
      jdbc-url: jdbc:mysql://127.0.0.1:3306/db1
      username: root
      password: root
    db2:
      driver-class-name: com.mysql.cj.jdbc.Driver
      jdbc-url: jdbc:mysql://127.0.0.1:3306/db2
      username: root
      password: root
    hikari:
      maximum-pool-size: 5
      minimumIdle: 5
      idleTimeout: 600000
      connectionTimeout: 30000
      maxLifetime: 1800000

这里是配置mysql数据库的两个schema，db1和db2，当然也可以配置多个不同的数据库实例，修改相应的参数即可

2、将配置的多数据源与springboot整合

db1数据源

package com.test.demo.config.datasource;


import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
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.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.support.TransactionTemplate;

import javax.sql.DataSource;

@Configuration
@MapperScan(basePackages = "com.test.demo.mapper.db1", sqlSessionTemplateRef = "db1SqlSessionTemplate", sqlSessionFactoryRef = "db1SqlSessionFactory")
public class Db1DataSourceConfig {
    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.db1")
    public DataSource db1DataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean
    public SqlSessionFactory db1SqlSessionFactory(@Qualifier("db1DataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
        configuration.setMapUnderscoreToCamelCase(true);
        bean.setConfiguration(configuration);
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/db1/*.xml"));
        return bean.getObject();
    }

    @Bean
    public DataSourceTransactionManager db1TransactionManager(@Qualifier("db1DataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean
    public SqlSessionTemplate db1SqlSessionTemplate(@Qualifier("db1SqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }

    @Bean
    public TransactionTemplate db1TransactionTemplate(@Qualifier("db1TransactionManager") DataSourceTransactionManager dataSourceTransactionManager) {
        return new TransactionTemplate(dataSourceTransactionManager);
    }
}

db2数据源

package com.test.demo.config.datasource;


import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
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.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.support.TransactionTemplate;

import javax.sql.DataSource;

@Configuration
@MapperScan(basePackages = "com.test.demo.mapper.db2", sqlSessionTemplateRef = "db2SqlSessionTemplate", sqlSessionFactoryRef = "db2SqlSessionFactory")
public class Db2DataSourceConfig {
    /**
     * 配置db2的数据源
     * @return
     */
    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.db2")
    public DataSource db2DataSource() {
        return DataSourceBuilder.create().build();
    }

    /**
     * 配置该数据源的sql会话工厂
     * @param dataSource
     * @return
     * @throws Exception
     */
    @Bean
    public SqlSessionFactory db2SqlSessionFactory(@Qualifier("db2DataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
        configuration.setMapUnderscoreToCamelCase(true);
        bean.setConfiguration(configuration);

        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/db2/*.xml"));
        return bean.getObject();
    }


    /**
     * 配置该数据源的事务管理器
     * @param dataSource
     * @return
     */
    @Bean
    public DataSourceTransactionManager db2TransactionManager(@Qualifier("db2DataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    /**
     * 配置db2数据源的sql会话模板
     * @param sqlSessionFactory
     * @return
     */
    @Bean
    public SqlSessionTemplate db2SqlSessionTemplate(@Qualifier("db2SqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }


    /**
     * 配置db2数据源的事务模板
     * @param dataSourceTransactionManager
     * @return
     */
    @Bean
    public TransactionTemplate db2TransactionTemplate(@Qualifier("db2TransactionManager") DataSourceTransactionManager dataSourceTransactionManager) {
        return new TransactionTemplate(dataSourceTransactionManager);
    }
}

3、使用

分别将不同数据源的mapper xml文件放入上面配置的对应的路径下，启动项目即可