Lucene .NET 搜索不返回任何结果

Posted 2023-04-13

【中文标题】Lucene .NET 搜索不返回任何结果

【英文标题】：Lucene .NET Search returns no Results

【发布时间】：2021-12-02 15:10:57

【问题描述】：

我一直试图让 Lucene .NET 在我的 API 中工作，但它总是返回 0 结果。 我在这里写的所有东西都封装在一个单例服务中，我的 API 控制器使用它。

我如何创建索引：

public async Task<bool> CreateSearchArtefacts()

    var analyzer = new StandardAnalyzer(AppLuceneVersion);
    var indexConfig = new IndexWriterConfig(AppLuceneVersion, analyzer);
    using (var dir = FSDirectory.Open(IndexPath))
    
        using (IndexWriter writer = new IndexWriter(dir, indexConfig))
        
            foreach (var element in this.data)
            
                Document doc = new Document
                
                    new TextField("Title", element.Title, Field.Store.YES),
                    new StringField("Author", element.Author, Field.Store.YES),
                    new TextField("Description", element.Description, Field.Store.NO)
                ;

                writer.AddDocument(doc);
                this.logger.LogInformation(element.Title + " added.");
            

            this.logger.LogInformation("All Books added.");
            writer.Commit();
        ;
    ;

    return true;

这就是我搜索它的方式：

public async Task<SearchResultsCollection> SearchSingleTerms(string term, string search, int count)

    this.logger.LogInformation("Searching Term "+ term + " for " + search);
    var phrase = new TermQuery(new Term(term, search));

    var analyzer = new StandardAnalyzer(AppLuceneVersion);
    var indexConfig = new IndexWriterConfig(AppLuceneVersion, analyzer);
    var sendList = new List<SearchResult>();
    using (var dir = FSDirectory.Open(IndexPath))
    
        using (var writer = new IndexWriter(dir, indexConfig))
        
            var reader = writer.GetReader(true);
            var searcher = new IndexSearcher(reader);
            var hits = searcher.Search(phrase, count  /* top 20 */).ScoreDocs;

            this.logger.LogInformation("Results found: " + hits.Length);
            foreach (var item in hits)
            
                var foundDoc = searcher.Doc(item.Doc);
                sendList.Add(new SearchResult()
                
                    Author = foundDoc.Get("Author"),
                    Title = foundDoc.Get("Title"),
                    Description = foundDoc.Get("Description")
                );
            

            writer.Flush(triggerMerge: false, applyAllDeletes: false);
        ;
    ;

    return new SearchResultsCollection()  Count = count, Results = sendList.ToArray() ;

我将 Lucene.Net 4.8.0-beta00014 与 .NET Core 3.1 一起使用

任何帮助表示赞赏！

【参考方案1】：

找到了。 我必须将短语的字符串参数转换为字符串值。

public async Task<SearchResultsCollection> SearchSingleTerms(string term, string search, int count)

    this.logger.LogInformation("Searching Term "+ term + " for " + search);
    var phrase = new TermQuery(new Term(term.ToString(), search.ToString()));

    var analyzer = new StandardAnalyzer(AppLuceneVersion);
    var indexConfig = new IndexWriterConfig(AppLuceneVersion, analyzer);
    var sendList = new List<SearchResult>();
    using (var dir = FSDirectory.Open(IndexPath))
    
        using (var writer = new IndexWriter(dir, indexConfig))
        
            var reader = writer.GetReader(true);
            var searcher = new IndexSearcher(reader);
            var hits = searcher.Search(phrase, count  /* top 20 */).ScoreDocs;

            this.logger.LogInformation("Results found: " + hits.Length);
            foreach (var item in hits)
            
                var foundDoc = searcher.Doc(item.Doc);
                sendList.Add(new SearchResult()
                
                    Author = foundDoc.Get("Author"),
                    Title = foundDoc.Get("Title"),
                    Description = foundDoc.Get("Description")
                );
            

            writer.Flush(triggerMerge: false, applyAllDeletes: false);
        ;
    ;

    return new SearchResultsCollection()  Count = count, Results = sendList.ToArray() ;