code: private ThriftConnection<T> obtainRawInternalConnection(ThriftServerInfo serverInfo)
  			throws ThriftConnectionPoolException {
  		// 判断单服务还是多服务模式
  		ThriftConnection<T> connection;
  		if (this.thriftServiceType == ThriftServiceType.SINGLE_INTERFACE) {
  			connection = new DefaultThriftConnection<>(serverInfo.getHost(), serverInfo.getPort(),
  					this.connectionTimeOut, this.config.getThriftProtocol(), this.config.getClientClass());
  		} else {
  			connection = new MulitServiceThriftConnecion<>(serverInfo.getHost(), serverInfo.getPort(),
  					this.connectionTimeOut, this.config.getThriftProtocol(), this.config.getThriftClientClasses());
  		}
  		return connection;
  	}
docs: 根据配置获取原始连接的方法
  
  @param serverInfo
  thrift服务器信息
  @return thrift客户端连接对象
  @throws ThriftConnectionPoolException
  当获取连接出现问题时抛出该异常