--TransportClient
TransportClient旨在被Java高级REST客户端取代，该客户端执行HTTP请求而不是序列化的Java请求。 在即将到来的Elasticsearch版本中将不赞成使用TransportClient，建议使用Java高级REST客户端。
The Java REST Client comes in 2 flavors:
Java Low Level REST Client: the official low-level client for Elasticsearch. It allows to communicate with an Elasticsearch cluster through http. Leaves requests marshalling and responses un-marshalling to users. It is compatible with all Elasticsearch versions.
Java High Level REST Client: the official high-level client for Elasticsearch. Based on the low-level client, it exposes API specific methods and takes care of requests marshalling and responses un-marshalling.
