一个SpringBoot项目，同时连接两个数据库：比如一个是Mysql数据库，一个是oracle数据库（啥数据库都一样，连接两个同为oracle的数据库，或两个不同的数据库，只需要更改对应的driver-class-name和jdbc-url等即可）注意：连接什么数据库，要引入对应数据库的包。

第一步：

导入pom

<dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.1.0</version>
</dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><scope>runtime</scope>
</dependency>

第二步：

修改application.yml配置文件（我采用本地的，IP地址是一致的，实际开发中，是两台云服务，两台MySQL地址进行主从读写）

    mysql1:driver-class-name: com.mysql.cj.jdbc.DriverjdbcUrl: jdbc:mysql://localhost:3306/test?useSSL=false&useUnicode=true&characterEncoding=UTF-8&serverTimezone=GMT%2B8username: "root"password: "12345678"type: com.alibaba.druid.pool.DruidDataSourcemysql2:driver-class-name: com.mysql.cj.jdbc.DriverjdbcUrl: jdbc:mysql://localhost:3306/test1?useSSL=false&useUnicode=true&characterEncoding=UTF-8&serverTimezone=GMT%2B8username: "root"password: "12345678"type: com.alibaba.druid.pool.DruidDataSource

注意格式上面spring.datasource省略了

第三步：

建造配置类：
（1）第一个库配置信息：

/*** 数据库leadnews_article*/
@Configuration
@MapperScan(basePackages = {"com.example.demo.mapper.db1"}, sqlSessionFactoryRef = "sqlSessionFactoryArticle")
public class DBSrcArticle {@Beanpublic SqlSessionFactory sqlSessionFactoryArticle(@Qualifier("mysql1") DataSource dataSource) throws Exception {MybatisSqlSessionFactoryBean sqlSessionFactory = new MybatisSqlSessionFactoryBean();sqlSessionFactory.setDataSource(dataSource);sqlSessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/db1/*.xml"));return sqlSessionFactory.getObject();}@Beanpublic SqlSessionTemplate sqlSessionTemplateArticle(@Qualifier("sqlSessionFactoryArticle") SqlSessionFactory sqlSessionFactory) throws Exception {return new SqlSessionTemplate(sqlSessionFactory);}
}

（2）第二个库配置

/*** 数据库leadnews_user*/
@Configuration
@MapperScan(basePackages = {"com.example.demo.mapper.db2"}, sqlSessionFactoryRef = "sqlSessionFactoryUser")
public class dBSrcUser {@Bean@Primarypublic SqlSessionFactory sqlSessionFactoryUser(@Qualifier("mysql2") DataSource dataSource) throws Exception {MybatisSqlSessionFactoryBean sqlSessionFactory = new MybatisSqlSessionFactoryBean();sqlSessionFactory.setDataSource(dataSource);sqlSessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/db2/*.xml"));return sqlSessionFactory.getObject();}@Bean@Primarypublic SqlSessionTemplate sqlSessionTemplateUser(@Qualifier("sqlSessionFactoryUser") SqlSessionFactory sqlSessionFactory) throws Exception {return new SqlSessionTemplate(sqlSessionFactory);}
}

（3）数据源配置：

/*** 数据源配置*/
@Configuration
public class DataSourceConfig {@Primary@Bean(name = "mysql1")@ConfigurationProperties(prefix = "spring.datasource.mysql1")public DataSource dBSrcArticle() {return DataSourceBuilder.create().build();}@Primary@Bean(name = "mysql2")@ConfigurationProperties(prefix = "spring.datasource.mysql2")public DataSource dBSrcUser() {return DataSourceBuilder.create().build();}
}

注意：连接两个以上的数据库，需要对mapper文件夹进行分包！

第四步：

在启动类中加上这三个注解：

@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})
@MapperScan(basePackages = {"com.example.demo.entity.db1"}, sqlSessionFactoryRef = "sqlSessionFactoryArticle")
@MapperScan(basePackages = {"com.example.demo.entity.db2"}, sqlSessionFactoryRef = "sqlSessionFactoryUser")

此时：已经可以访问两个数据库内容了。