摘要与高亮

查询非嵌套类型字段时使用查询摘要与高亮

以下示例使用匹配查询检索 description 字段中包含 tablestore 词条的数据，并使用 <b> 和 </b> 标记返回分片中的命中词条。description 字段为已启用摘要与高亮的 Text 字段。

String tableName = "example_table";
String indexName = "example_index";

MatchQuery matchQuery = new MatchQuery();
matchQuery.setFieldName("description");
matchQuery.setText("tablestore");

HighlightParameter highlightParameter = new HighlightParameter();
highlightParameter.setPreTag("<b>");
highlightParameter.setPostTag("</b>");

Highlight highlight = new Highlight();
highlight.addFieldHighlightParam("description", highlightParameter);

SearchQuery searchQuery = new SearchQuery();
searchQuery.setQuery(matchQuery);
searchQuery.setHighlight(highlight);
searchQuery.setLimit(10);

SearchRequest request = new SearchRequest(tableName, indexName, searchQuery);
SearchResponse response = client.search(request);
for (SearchHit hit : response.getSearchHits()) {
    HighlightResultItem resultItem = hit.getHighlightResultItem();
    if (resultItem == null) {
        continue;
    }
    HighlightField field = resultItem.getHighlightFieldByName("description");
    if (field != null) {
        System.out.println(field.getFragments());
    }
}

查询嵌套类型字段时使用查询摘要与高亮

以下示例用于使用NestedQuery功能查询表中Col_Nested嵌套类型字段中Level1_Col1_Nested子列的值能够匹配hangzhou shanghai的数据，并在返回结果中对查询词进行高亮显示。

MatchQuery matchQuery = new MatchQuery();
matchQuery.setFieldName("items.description");
matchQuery.setText("hangzhou");

HighlightParameter parameter = new HighlightParameter();
parameter.setPreTag("<em>");
parameter.setPostTag("</em>");
Highlight highlight = new Highlight();
highlight.addFieldHighlightParam("items.description", parameter);

InnerHits innerHits = new InnerHits();
innerHits.setLimit(3);
innerHits.setSort(new Sort(Arrays.asList(
        new ScoreSort(), new DocSort(SortOrder.ASC))));
innerHits.setHighlight(highlight);

NestedQuery nestedQuery = new NestedQuery();
nestedQuery.setPath("items");
nestedQuery.setQuery(matchQuery);
nestedQuery.setScoreMode(ScoreMode.None);
nestedQuery.setInnerHits(innerHits);

SearchQuery searchQuery = new SearchQuery();
searchQuery.setQuery(nestedQuery);

假设多层级嵌套类型字段Col_Nested中包括Level1_Col1_Text（Text类型）和Level1_Col2_Nested（Nested类型）两列，其中Level1_Col2_Nested嵌套类型字段包括Level2_Col1_Text子列。

以下示例用于通过在NestedQuery中添加BoolQuery对Col_Nested字段中的Level1_Col1_Text子列和Level1_Col2_Nested下的Level2_Col1_Text子列同时使用查询摘要与高亮功能。

public static void nestedQueryWithHighlighting(SyncClient client) {
    SearchRequest searchRequest = SearchRequest.newBuilder()
            .tableName("<TABLE_NAME>")
            .indexName("<SEARCH_INDEX_NAME>")
            .returnAllColumnsFromIndex(true)
            .searchQuery(SearchQuery.newBuilder()
                    .limit(5)
                    .query(QueryBuilders.nested()
                            .path("Col_Nested")
                            .scoreMode(ScoreMode.Min)
                            .query(QueryBuilders.bool()
                                    .should(QueryBuilders.match("Col_Nested.Level1_Col1_Text", "hangzhou shanghai"))
                                    .should(QueryBuilders.nested()
                                            .path("Col_Nested.Level1_Col2_Nested")
                                            .scoreMode(ScoreMode.Min)
                                            .query(QueryBuilders.match("Col_Nested.Level1_Col2_Nested.Level2_Col1_Text", "hangzhou shanghai"))
                                            .innerHits(InnerHits.newBuilder()
                                                    .highlight(Highlight.newBuilder()
                                                            .addFieldHighlightParam("Col_Nested.Level1_Col2_Nested.Level2_Col1_Text", HighlightParameter.newBuilder().build())
                                                            .build())
                                                    .build())))
                            .innerHits(InnerHits.newBuilder()
                                    .sort(new Sort(Arrays.asList(
                                            new ScoreSort(),
                                            new DocSort()
                                    )))
                                    .highlight(Highlight.newBuilder()
                                            .addFieldHighlightParam("Col_Nested.Level1_Col1_Text", HighlightParameter.newBuilder().build())
                                            .build())
                                    .build()))
                    .build())
            .build();
    SearchResponse resp = client.search(searchRequest);
    // 打印高亮结果。
    printSearchHit(resp.getSearchHits(), "");
}

/**
 * 打印searchHit内容。
 * @param searchHits searchHits
 * @param prefix Nested结构输出时，增加前缀以打印层次信息。
 */
private static void printSearchHit(List<SearchHit> searchHits, String prefix) {
    for (SearchHit searchHit : searchHits) {
        if (searchHit.getScore() != null) {
            System.out.printf("%s Score: %s
", prefix, searchHit.getScore());
        }

        if (searchHit.getOffset() != null) {
            System.out.printf("%s Offset: %s
", prefix, searchHit.getOffset());
        }

        if (searchHit.getRow() != null) {
            System.out.printf("%s Row: %s
", prefix, searchHit.getRow().toString());
        }

        // 打印各字段高亮分片结果。
        if (searchHit.getHighlightResultItem() != null) {
            System.out.printf("%s Highlight: 
", prefix);
            StringBuilder strBuilder = new StringBuilder();
            for (Map.Entry<String, HighlightField> entry : searchHit.getHighlightResultItem().getHighlightFields().entrySet()) {
                strBuilder.append(entry.getKey()).append(":").append("[");
                strBuilder.append(StringUtils.join(",", entry.getValue().getFragments())).append("]
");
            }
            System.out.printf("%s   %s", prefix, strBuilder);
        }

        // 嵌套类型高亮结果。
        for (SearchInnerHit searchInnerHit : searchHit.getSearchInnerHits().values()) {
            System.out.printf("%s Path: %s
", prefix, searchInnerHit.getPath());
            System.out.printf("%s InnerHit: 
", prefix);
            printSearchHit(searchInnerHit.getSubSearchHits(), prefix + "    ");
        }

        System.out.println();
    }
}