一：下载multidatasources-spring-boot-starter,并安装到本地
二：springboot项目中的pom文件加入依赖，地址如下
  <dependency>
    <groupId>com.yonyou.multidatasources</groupId>
    <artifactId>
      multidatasources-spring-boot-starter
    </artifactId>
    <version>0.9.1-SNAPSHOT</version>
  </dependency>
三：修改项目的配置文件application.yml，配置自己的数据源，其中datasource下一级约定为default、two、three、four、five,default为必配
  multi:
    datasource:
      default:
        driver-class-name: com.mysql.jdbc.Driver
        url: jdbc:mysql://127.0.0.1:3306/lin_infrastructure?useUnicode=true&characterEncoding=UTF-8 
        username: 
        password: 
      two:
        driver-class-name: com.mysql.jdbc.Driver
        url: jdbc:mysql://localhost:3306/db_slave1?useSSL=false&useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&allowMultiQueries=true
        username: 
        password: 
      three:
        driver-class-name: com.mysql.jdbc.Driver
        url: jdbc:mysql://localhost:3306/db_slave2?useSSL=false&useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&allowMultiQueries=true
        username: 
        password: 
四：在service层的方法上使用注解来切换数据库，枚举中DataSourceKey的DB_DEFAULT, DB_TWO, DB_THREE, DB_FOUR, DB_FIVE分别对应default、two、three、four、five,default
    示例：
    @TargetDataSource(dataSourceKey = DataSourceKey.DB_THREE)对应multi.datasource.three配置的数据源