微服务es搜索关键词，实现关键词高亮，来自头条的总结

在实现微服务中的Elasticsearch关键字高亮时，可以使用Elasticsearch的highlight功能。以下是一个简单的例子，展示了如何在Spring Boot应用中使用Elasticsearch RestHighLevelClient来执行搜索并实现关键字高亮。

import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightField;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
 
import java.io.IOException;
import java.util.Map;
 
@Service
public class SearchService {
 
    @Autowired
    private RestHighLevelClient client;
 
    public SearchResponse searchWithHighlight(String index, String field, String keyword) throws IOException {
        SearchRequest searchRequest = new SearchRequest(index);
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
 
        HighlightBuilder highlightBuilder = new HighlightBuilder();
        highlightBuilder.field(field).requireFieldMatch(false);
        searchSourceBuilder.highlighter(highlightBuilder);
 
        searchSourceBuilder.query(QueryBuilders.matchQuery(field, keyword));
 
        searchRequest.source(searchSourceBuilder);
        SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
 
        return searchResponse;
    }
 
    public void processSearchResponseWithHighlight(SearchResponse searchResponse) {
        for (var hit : searchResponse.getHits().getHits()) {
            Map<String, HighlightField> highlightFields = hit.getHighlightFields();
            HighlightField highlightField = highlightFields.get(/* 你要高亮的字段名 */);
            if (highlightField != null) {
                System.out.println(highlightField.getFragments()[0].string());
            }
        }