怎么做到像百度搜索高亮内容预览

        SearchRequestBuilder builder = getClient().prepareSearch(index);

		builder.setTypes(type);

		builder.setFrom(start);

		builder.setSize(row);

		

        //设置高亮显示,字体设置为红色

        HighlightBuilder highlightBuilder = new HighlightBuilder().field("title").field("describe").requireFieldMatch(false);

        highlightBuilder.preTags("<span style=\"color:red\">");

        highlightBuilder.postTags("</span>");

        builder.highlighter(highlightBuilder);



		builder.setSearchType(SearchType.DFS_QUERY_THEN_FETCH);

		

	这是查询的时候添加；

		builder.setExplain(true);

		SearchResponse searchResponse = builder.get();

		

		SearchHits hits = searchResponse.getHits();

		long total = hits.getTotalHits();

		Map<String, Object> map = new HashMap<String,Object>();

		SearchHit[] hits2 = hits.getHits();

		map.put("count", total);

		List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();

		for (SearchHit searchHit : hits2) {

			Map<String, HighlightField> highlightFields = searchHit.getHighlightFields();

			HighlightField highlightField = highlightFields.get("title");

			Map<String, Object> source = searchHit.getSourceAsMap();

			if(highlightField!=null){

				Text[] fragments = highlightField.fragments();

				String name = "";

				for (Text text : fragments) {

					name+=text;

				}

				source.put("title", name);

			}

			HighlightField highlightField2 = highlightFields.get("describe");

			if(highlightField2!=null){

				Text[] fragments = highlightField2.fragments();

				String describe = "";

				for (Text text : fragments) {

					describe+=text;

				}

				source.put("describe", describe);

			}

			list.add(source);

		}

		map.put("dataList", list);

		return map;

这是获取高亮的结果

有高亮的语法

我们之前高亮是这样实现的
1.  query的文字部分拆出来单独过分词器做分词（跟title、content字段同款分词器）
2. 完整的query丢ES里做召回
3. 把文档的结果连同分词结果一起返回前端
4. 前端根据分词结果对文章/标题进行高亮