springboot如何连接两个数据库(多个)

目录

• 一、启动类
• 二、application.yml文件
• 三、创建配置类
• 四 、结构
• 五、多数据源的事物问题

一、启动类

1.启动类需要不用加mybatis的@MapperScan注解

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

二、application.yml文件

配置俩个或多个数据库连接，我这里用的是postgresql，用mysql等也是一样

spring:
  datasource:
#    driver-class-name: org.postgresql.Driver
#    url: jdbc:postgresql://127.0.0.1/aaa
#    username: root
#    password: root
      one:
        driver-class-name: org.postgresql.Driver
        url: jdbc:postgresql://127.0.0.1/aaa
        username: root
        password: root
      two:
        driver-class-name: org.postgresql.Driver
        url: jdbc:postgresql://127.0.0.1/bbb
        username: root
        password: root

三、创建配置类

1.注意：@MapperScan 的basePackages就是你包的路径 ，

sqlSessionFactoryRef 可以随便起名 但是着两个类不能重复！

One配置类

package com.wys.config;
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.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
import org.springframework.boot.context.properties.ConfigurationProperties;
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.DriverManagerDataSource;
import javax.sql.DataSource;
/**
 * @program:
 * @description: 数据库配置1
 * @author: wys
 * @create: 2019-12-03 16:20
 **/
@Configuration
@MapperScan(basePackages = "com.wys.mapper.**", sqlSessionFactoryRef = "oneSqlSessionFactory")
public class OneDataSourceConfig {
    @Value("${spring.datasource.one.driver-class-name}")
    String driverClass;
    @Value("${spring.datasource.one.url}")
    String url;
    @Value("${spring.datasource.one.username}")
    String userName;
    @Value("${spring.datasource.one.password}")
    String passWord;
    @Primary
    @Bean(name = "oneDataSource")
    @ConfigurationProperties("spring.datasource.one")
    public DataSource masterDataSource() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName(driverClass);
        dataSource.setUrl(url);
        dataSource.setUsername(userName);
        dataSource.setPassword(passWord);
        return dataSource;
    }
    @Bean(name = "oneSqlSessionFactory")
    public SqlSessionFactory sqlSessionFactory(@Qualifier("oneDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean sessionFactoryBean = new SqlSessionFactoryBean();
        sessionFactoryBean.setDataSource(dataSource);
        sessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources("classpath:mybatis/mapper-postgre/*.xml"));
        return sessionFactoryBean.getObject();
    }
    @Bean(name = "oneSqlSessionTemplate")
    public SqlSessionTemplate sqlSessionFactoryTemplate(@Qualifier("oneSqlSessionFactory")SqlSessionFactory sqlSessionFactory ) throws Exception {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

Two配置类

package com.wys.config;
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.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
import org.springframework.boot.context.properties.ConfigurationProperties;
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.DriverManagerDataSource;
import javax.sql.DataSource;
/**
 * @program:
 * @description: 数据库配置2
 * @author: wys
 * @create: 2019-12-03 17:03
 **/
@Configuration
@MapperScan(basePackages = "com.wys.mappers",sqlSessionFactoryRef = "twoSqlSessionFactory")
public class TwoDataSourceConfig {
    @Value("${spring.datasource.two.driver-class-name}")
    String driverClass;
    @Value("${spring.datasource.two.url}")
    String url;
    @Value("${spring.datasource.two.username}")
    String userName;
    @Value("${spring.datasource.two.password}")
    String passWord;

    @Bean(name = "twoDataSource")
    @ConfigurationProperties("spring.datasource.two")
    public DataSource masterDataSource(){
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName(driverClass);
        dataSource.setUrl(url);
        dataSource.setUsername(userName);
        dataSource.setPassword(passWord);
        return dataSource;
    }
    @Bean(name = "twoSqlSessionFactory")
    public SqlSessionFactory sqlSessionFactory(@Qualifier("twoDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean sessionFactoryBean = new SqlSessionFactoryBean();
        sessionFactoryBean.setDataSource(dataSource);
        sessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources("classpath:mybatis/mapper-postgres/*.xml"));
        return sessionFactoryBean.getObject();
    }

    @Bean(name = "twoSqlSessionTemplate")
    public SqlSessionTemplate sqlSessionFactoryTemplate(@Qualifier("twoSqlSessionFactory")SqlSessionFactory sqlSessionFactory ) throws Exception {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

四 、结构

可能有人不清楚项目的结构，我在下面放了一张类结构图，能更清晰和方便理解。

注意：和之前的项目的主要区别就是 mapper包多了一个，mapper的xml包也多了一个，不同的数据库mapper放到不同的包内就可以了。

五、多数据源的事物问题

在使用多数据源时，有可能会遇到事物失败的问题。我单独总结了一个文章。需要的话可以阅读一下。@Transactional注解异常报错之多数据源.

以上为个人经验，希望能给大家一个参考，也希望大家多多支持我们。