spring中應用模板模式封裝ElasticsearchTemplate

時間 2020-01-02

標籤 spring 應用模板模式封裝 elasticsearchtemplate 欄目 Spring 简体版

原文原文鏈接

1.查詢
json

@Override 
public <T> FacetedPage<T> queryForPage(SearchQuery query, Class<T> clazz, SearchResultMapper mapper) { 
    SearchResponse response = doSearch(prepareSearch(query, clazz), query); 
    return mapper.mapResults(response, clazz, query.getPageable()); 
}

主要邏輯在doSearch方法中瀏覽器

private SearchResponse doSearch(SearchRequestBuilder searchRequest, SearchQuery searchQuery) { 
    if (searchQuery.getFilter() != null) { 
        searchRequest.setPostFilter(searchQuery.getFilter()); 
    } 

    if (CollectionUtils.isNotEmpty(searchQuery.getElasticsearchSorts())) { 
        for (SortBuilder sort : searchQuery.getElasticsearchSorts()) { 
            searchRequest.addSort(sort); 
        } 
    } 

    if (CollectionUtils.isNotEmpty(searchQuery.getFacets())) { 
        for (FacetRequest facetRequest : searchQuery.getFacets()) { 
            FacetBuilder facet = facetRequest.getFacet(); 
            if (facetRequest.applyQueryFilter() && searchQuery.getFilter() != null) { 
                facet.facetFilter(searchQuery.getFilter()); 
            } 
            searchRequest.addFacet(facet); 
        } 
    } 

    if (searchQuery.getHighlightFields() != null) { 
        for (HighlightBuilder.Field highlightField : searchQuery.getHighlightFields()) { 
            searchRequest.addHighlightedField(highlightField); 
        } 
    } 

    if (CollectionUtils.isNotEmpty(searchQuery.getAggregations())) { 
        for (AbstractAggregationBuilder aggregationBuilder : searchQuery.getAggregations()) { 
            searchRequest.addAggregation(aggregationBuilder); 
        } 
    } 
    return getSearchResponse(searchRequest.setQuery(searchQuery.getQuery()).execute()); 
}

該方法主要處理邏輯tomcat

1.加入順序參數mvc

2.設置參數過濾參數app

3.設置高亮顯示參數elasticsearch

結果處理由組件 ResultsMapper 結果映射器處理ide

public interface ResultsMapper extends SearchResultMapper, GetResultMapper, MultiGetResultMapper { 學習

EntityMapper getEntityMapper();

}
ui

public interface SearchResultMapper { this

<T> FacetedPage<T> mapResults(SearchResponse response, Class<T> clazz, Pageable pageable);

}

初始化映射器

public ElasticsearchTemplate(Client client, ElasticsearchConverter elasticsearchConverter, ResultsMapper resultsMapper) {
this.client = client;
this.elasticsearchConverter = (elasticsearchConverter == null) ? new MappingElasticsearchConverter(
new SimpleElasticsearchMappingContext()) : elasticsearchConverter;
this.resultsMapper = (resultsMapper == null) ? new DefaultResultMapper(this.elasticsearchConverter.getMappingContext()) : resultsMapper;
}

默認實現的映射器DefaultResultMapper

@Override 
public <T> FacetedPage<T> mapResults(SearchResponse response, Class<T> clazz, Pageable pageable) { 
    long totalHits = response.getHits().totalHits(); 
    List<T> results = new ArrayList<T>(); 
    for (SearchHit hit : response.getHits()) { 
        if (hit != null) { 
            T result = null; 
            if (!Strings.isNullOrEmpty(hit.sourceAsString())) { 
                result = mapEntity(hit.sourceAsString(), clazz); 
            } else { 
                result = mapEntity(hit.getFields().values(), clazz); 
            } 
            setPersistentEntityId(result, hit.getId(), clazz); 
            results.add(result); 
        } 
    } 
    List<FacetResult> facets = new ArrayList<FacetResult>(); 
    if (response.getFacets() != null) { 
        for (Facet facet : response.getFacets()) { 
            FacetResult facetResult = DefaultFacetMapper.parse(facet); 
            if (facetResult != null) { 
                facets.add(facetResult); 
            } 
        } 
    } 

    return new FacetedPageImpl<T>(results, pageable, totalHits, facets); 
}

主要是講json格式轉換爲指定Class類型bean對象

##2.自主擴展

搜索邏輯絕大部分能夠固化封裝，只有結果處理須要留出用戶擴展空間，能夠用回調的方式，定義接口，參數中傳入匿名實現

@Override
public <T> T query(SearchQuery query, ResultsExtractor<T> resultsExtractor) {
SearchResponse response = doSearch(prepareSearch(query), query);
return resultsExtractor.extract(response);
}

public interface ResultsExtractor<T> {