code: public   String getDocument(String indexName,   String documentId, Map<String, Object> options) throws ElasticSearchException{
  		return getDocument(  indexName,  _doc,     documentId,   options);
  	}
docs: 获取json格式文档，通过options设置获取文档的参数
  @param indexName
  @param documentId
  @param options
  @return
  @throws ElasticSearchException