code: public   MapSearchHit getDocumentHit(String indexName, String indexType,String documentId) throws ElasticSearchException{
  		return getDocumentHit(indexName, indexType,documentId,(Map<String,Object> )null);
  	}
docs: 获取文档MapSearchHit对象，封装了索引文档的所有属性数据
  @param indexName
  @param indexType
  @param documentId
  @return
  @throws ElasticSearchException