如何使用 Spring 数据 elasticsearch 提供高亮显示

Question

似乎 SpringData ES 不提供 classes 来获取由 ES 编辑的 return 亮点。 Spring 数据可以 return 对象列表，但 ES 编辑的 Json return 中的高亮部分位于 "ElasticSearchTemplate" 未处理的单独部分class.

代码示例：-

QueryBuilder query = QueryBuilders.matchQuery("name","tom"); 
SearchQuery searchQuery =new NativeSearchQueryBuilder().withQuery(query).
                               with HighlightFields(new Field("name")).build();
List<ESDocument> publications = elasticsearchTemplate.queryForList
                                                (searchQuery, ESDocument.class);

我可能是错的，但我想不出只使用 SpringDataES。有人可以 post 举例说明我们如何使用 Spring Data ES 获得亮点？

提前致谢！

Answer 1

根据 spring data elasticsearch 中的测试用例，我找到了解决方案：

这会有所帮助。

@Test
public void shouldReturnHighlightedFieldsForGivenQueryAndFields() {

    //given
    String documentId = randomNumeric(5);
    String actualMessage = "some test message";
    String highlightedMessage = "some <em>test</em> message";

    SampleEntity sampleEntity = SampleEntity.builder().id(documentId)
            .message(actualMessage)
            .version(System.currentTimeMillis()).build();

    IndexQuery indexQuery = getIndexQuery(sampleEntity);

    elasticsearchTemplate.index(indexQuery);
    elasticsearchTemplate.refresh(SampleEntity.class);

    SearchQuery searchQuery = new NativeSearchQueryBuilder()
            .withQuery(termQuery("message", "test"))
            .withHighlightFields(new HighlightBuilder.Field("message"))
            .build();

    Page<SampleEntity> sampleEntities = elasticsearchTemplate.queryForPage(searchQuery, SampleEntity.class, new SearchResultMapper() {
        @Override
        public <T> Page<T> mapResults(SearchResponse response, Class<T> clazz, Pageable pageable) {
            List<SampleEntity> chunk = new ArrayList<SampleEntity>();
            for (SearchHit searchHit : response.getHits()) {
                if (response.getHits().getHits().length <= 0) {
                    return null;
                }
                SampleEntity user = new SampleEntity();
                user.setId(searchHit.getId());
                user.setMessage((String) searchHit.getSource().get("message"));
                user.setHighlightedMessage(searchHit.getHighlightFields().get("message").fragments()[0].toString());
                chunk.add(user);
            }
            if (chunk.size() > 0) {
                return new PageImpl<T>((List<T>) chunk);
            }
            return null;
        }
    });

    assertThat(sampleEntities.getContent().get(0).getHighlightedMessage(), is(highlightedMessage));
}

Answer 2

实际上，您可以使用自定义 ResultExtractor 执行以下操作：

QueryBuilder query = QueryBuilders.matchQuery("name", "tom"); 
SearchQuery searchQuery = new NativeSearchQueryBuilder()
                           .withQuery(query)
                           .withHighlightFields(new Field("name")).build();
return elasticsearchTemplate.query(searchQuery.build(), new CustomResultExtractor());

然后

public class CustomResultExtractor implements ResultsExtractor<List<MyClass>> {

private final DefaultEntityMapper defaultEntityMapper;

public CustomResultExtractor() {
    defaultEntityMapper = new DefaultEntityMapper();
}


@Override
public List<MyClass> extract(SearchResponse response) {
    return StreamSupport.stream(response.getHits().spliterator(), false) 
        .map(this::searchHitToMyClass) 
        .collect(Collectors.toList());
}

private MyClass searchHitToMyClass(SearchHit searchHit) {
    MyElasticSearchObject myObject;
    try {
        myObject = defaultEntityMapper.mapToObject(searchHit.getSourceAsString(), MyElasticSearchObject.class);
    } catch (IOException e) {
        throw new ElasticsearchException("failed to map source [ " + searchHit.getSourceAsString() + "] to class " + MyElasticSearchObject.class.getSimpleName(), e);
    }
    List<String> highlights = searchHit.getHighlightFields().values()
        .stream() 
        .flatMap(highlightField -> Arrays.stream(highlightField.fragments())) 
        .map(Text::string) 
        .collect(Collectors.toList());
    // Or whatever you want to do with the highlights
    return new MyClass(myObject, highlights);
}}

请注意，我使用了列表，但您可以使用任何其他可迭代数据结构。此外，您还可以对亮点进行其他操作。这里我简单罗列一下。

Answer 3

第一个答案确实有效，但我发现它的返回结果存在一些可分页的问题，显示的总元素错误 toalpages.Arter 我检查了 DefaultResultMapper 实现，返回的语句应该是 return new AggregatedPageImpl((List<T>) chunk, pageable, totalHits, response.getAggregations(), response.getScrollId(), maxScore);，然后它与 paging.wish 合作，我可以帮助你们~

Answer 4

Spring Data Elasticsearch 4.0 现在有 SearchPage 结果类型，如果我们需要 return 突出显示结果，这会让事情变得更容易一些：

这是一个工作示例：

    String query = "(id:123 OR id:456) AND (database:UCLF) AND (services:(sealer?), services:electronic*)"
    
    NativeSearchQuery searchQuery = new NativeSearchQueryBuilder()
            .withPageable(pageable)
            .withQuery(queryStringQuery(query))
            .withSourceFilter(sourceFilter)
            .withHighlightFields(new HighlightBuilder.Field("goodsAndServices"))
            .build();
    
    
    SearchHits<Trademark> searchHits = template.search(searchQuery, Trademark.class, IndexCoordinates.of("trademark"));
    SearchPage<Trademark> page = SearchHitSupport.searchPageFor(searchHits, searchQuery.getPageable());
    return (Page<Trademark>) SearchHitSupport.unwrapSearchHits(page);

这将是 json 中 Page 对象的响应：

{
    "content": [
        {
            "id": "123",
            "score": 12.10748,
            "sortValues": [],
            "content": {
                "_id": "1P0XzXIBdRyrchmFplEA",
                "trademarkIdentifier": "abc234",
                "goodsAndServices": null,
                "language": "EN",
                "niceClass": "2",
                "sequence": null,
                "database": "UCLF",
                "taggedResult": null
            },
            "highlightFields": {
                "goodsAndServices": [
                    "VARNISHES, <em>SEALERS</em>, AND NATURAL WOOD FINISHES"
                ]
            }
        }
    ],
    "pageable": {
        "sort": {
            "unsorted": true,
            "sorted": false,
            "empty": true
        },
        "offset": 0,
        "pageNumber": 0,
        "pageSize": 20,
        "unpaged": false,
        "paged": true
    },
    "searchHits": {
        "totalHits": 1,
        "totalHitsRelation": "EQUAL_TO",
        "maxScore": 12.10748,
        "scrollId": null,
        "searchHits": [
            {
                "id": "123",
                "score": 12.10748,
                "sortValues": [],
                "content": {
                    "_id": "1P0XzXIBdRyrchmFplEA",
                    "trademarkIdentifier": "abc234",
                    "goodsAndServices": null,
                    "language": "EN",
                    "niceClass": "2",
                    "sequence": null,
                    "database": "UCLF",
                    "taggedResult": null
                },
                "highlightFields": {
                    "goodsAndServices": [
                        "VARNISHES, <em>SEALERS</em>, AND NATURAL WOOD FINISHES"
                    ]
                }
            }
        ],
        "aggregations": null,
        "empty": false
    },
    "totalPages": 1,
    "totalElements": 1,
    "size": 20,
    "number": 0,
    "numberOfElements": 1,
    "last": true,
    "first": true,
    "sort": {
        "unsorted": true,
        "sorted": false,
        "empty": true
    },
    "empty": false
}

如何使用 Spring 数据 elasticsearch 提供高亮显示

How to provide highlighting with Spring data elasticsearch

elasticsearch

spring-data

spring-data-elasticsearch