SpringBoot如何整合多个数据源，看这篇就够了

一个程序员的成长

发布于 2020-11-25 14:25:42

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发布于 2020-11-25 14:25:42

SpringBoot现在是很多很多公司应用的后端框架，因为它搭建快，能更好、更快速的整合其他第三方。那么随着业务的不断扩展，业务量的增加，这时候就会牵扯到分库分表，虽然这个词听起来很熟悉，作为程序员也很容易理解，但是我想应该也有不少读者没接触过分库分表，今天我们不聊如何分库分表，而是聊SpringBoot如何整合多个数据源的事情。也就是如何接入不同的（多个）数据库。

我们直接开始，我们直接创建一个干净的SpringBoot应用。

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.0.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>1.3.2</version>
</dependency>

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <scope>runtime</scope>
</dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>

<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.8</version>
</dependency>

引入需要的maven坐标，那么我们这个工程就算搭建起来了，接下来就是配置，如何让SpringBoot整合两个Mysql数据源。首先我们在本地创建两个数据库test1和test2，同时在里面创建两个结构一样的表。

CREATE TABLE `user` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '用户ID',
  `username` varchar(100) CHARACTER SET utf8 NOT NULL COMMENT '用户名',
  `password` varchar(100) NOT NULL COMMENT '密码',
  `create_time` datetime DEFAULT NULL COMMENT '创建时间',
  PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=3 DEFAULT CHARSET=latin1;

在我们的工程中配置application.yml文件，将数据库的信息配置进去

spring:
  datasource:
    test1:
      driver-class-name: com.mysql.cj.jdbc.Driver
      jdbc-url: jdbc:mysql://localhost:3306/test1?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
      username: root
      password: 1234

    test2:
      driver-class-name: com.mysql.cj.jdbc.Driver
      jdbc-url: jdbc:mysql://localhost:3306/test2?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
      username: root
      password: 1234

接下来就是写我们的配置类了，这也是整合多个数据源最为关键的部分。

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.context.annotation.Primary;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;

/**
 * @ClassName DataSource2Config
 * @Description TODO
 * @Auther lbt
 * @Date 2019/6/28/028 10:07
 * @Version 1.0
 */
@Configuration
@MapperScan(basePackages = "com.example.mapper.test1", sqlSessionFactoryRef = "test1SqlSessionFactory")
public class DataSource1Config {


    @Bean(name = "test1DataSource")
    @ConfigurationProperties(prefix = "spring.datasource.test1")
    @Primary
    public DataSource test1DataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "test1SqlSessionFactory")
    @Primary
    public SqlSessionFactory test1SqlSessionFactory(@Qualifier("test1DataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        return bean.getObject();
    }

    @Bean(name = "test1TransactionManager")
    @Primary
    public DataSourceTransactionManager test1TransactionManager(@Qualifier("test1DataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean(name = "test1SqlSessionTemplate")
    @Primary
    public SqlSessionTemplate test1SqlSessionTemplate(@Qualifier("test1SqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

第二个数据源的配置

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.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;

@Configuration
@MapperScan(basePackages = "com.example.mapper.test2", sqlSessionFactoryRef = "test2SqlSessionFactory")
public class DataSource2Config {


    @Bean(name = "test2DataSource")
    @ConfigurationProperties(prefix = "spring.datasource.test2")
    public DataSource test2DataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "test2SqlSessionFactory")
    public SqlSessionFactory test2SqlSessionFactory(@Qualifier("test2DataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        return bean.getObject();
    }

    @Bean(name = "test2TransactionManager")
    public DataSourceTransactionManager test2TransactionManager(@Qualifier("test2DataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean(name = "test2SqlSessionTemplate")
    public SqlSessionTemplate test2SqlSessionTemplate(@Qualifier("test2SqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

这样我们整个的配置其实就算好了，我们接下来写一个Controller类来测试一下，我们整合的数据源是不是真的可以用呢？

@RestController
public class TestController {

    @Autowired
    private User1Service user1Service;

    @Autowired
    private User2Service user2Service;

    @RequestMapping("/user1")
    public Object user1Controller() {

        List<UserPo> all = user1Service.findAll();

        return all;
    }

    @RequestMapping("/user2")
    public Object user2Controller() {

        List<UserPo> all = user2Service.findAll();

        return all;
    }
}

我写了个两个Controller方法，分别访问不同的接口，我们来看下访问结果。

当我们访问user1的时候返回如下：