code: public <T> ESDatas<T> searchAllParallel(String index,  final int fetchSize ,ScrollHandler<T> scrollHandler,final Class<T> type,int max) throws ElasticSearchException{
  		if(!this.client.isV1()) {
  			SliceScroll sliceScroll = new SliceScroll() {
  				@Override
  				public String buildSliceDsl(int sliceId, int max) {
  					StringBuilder builder = new StringBuilder();
  					String sliceDsl = builder.append("{\"slice\": {\"id\": ").append(sliceId).append(",\"max\": ")
  							.append(max).append("},\"size\":").append(fetchSize).append(",\"query\": {\"match_all\": {}},\"sort\": [\"_doc\"]}").toString();
  					return sliceDsl;
  //				return buildSliceDsl(i,max, params, dslTemplate);
  				}
  			};
  
  			return _slice(index + "/_search", scrollHandler, type, max, "1m", sliceScroll);
  		}
  		else{
  			StringBuilder builder = new StringBuilder();
  			String queryAll = builder.append("{ \"size\":").append(fetchSize).append(",\"query\": {\"match_all\": {}},\"sort\": [\"_doc\"]}").toString();
  			builder.setLength(0);
  			return this.scrollParallel(builder.append(index).append("/_search").toString(),queryAll,"10m",type,scrollHandler);
  		}
  
  	}
docs: 并行检索索引所有数据
  @param index
  @param fetchSize 指定每批次返回的数据，不指定默认为5000
  @param scrollHandler 每批数据处理方法
  @param type
  @param <T>
  @return
  @throws ElasticSearchException