无法使用lucene删除文档IndexWriter.deleteDocuments(term)

时间:2017-02-17 09:21:39

标签: java lucene

现在这两天一直在努力,只是无法用indexWriter.deleteDocuments(term)

删除文档

在这里,我将放置将要进行测试的代码,希望有人可以指出我做错了什么,已经尝试过的事情:

  1. 将lucene版本从2.x更新为5.x
  2. 使用indexWriter.deleteDocuments()代替indexReader.deleteDocuments()
  3. indexOption配置为NONEDOCS_AND_FREQS_AND_POSITIONS_AND_OFFSETS
  4. 这里是代码:

    import org.apache.lucene.analysis.core.SimpleAnalyzer;
    import org.apache.lucene.document.Document;
    import org.apache.lucene.document.Field;
    import org.apache.lucene.document.FieldType;
    import org.apache.lucene.index.*;
    import org.apache.lucene.queryparser.classic.ParseException;
    import org.apache.lucene.queryparser.classic.QueryParser;
    import org.apache.lucene.search.IndexSearcher;
    import org.apache.lucene.search.Query;
    import org.apache.lucene.search.ScoreDoc;
    import org.apache.lucene.store.Directory;
    import org.apache.lucene.store.FSDirectory;
    
    import java.io.IOException;
    import java.nio.file.Paths;
    
    public class TestSearch {
        static SimpleAnalyzer analyzer = new SimpleAnalyzer();
    
        public static void main(String[] argvs) throws IOException, ParseException {
            generateIndex("5836962b0293a47b09d345f1");
            query("5836962b0293a47b09d345f1");
            delete("5836962b0293a47b09d345f1");
            query("5836962b0293a47b09d345f1");
    
        }
    
        public static void generateIndex(String id) throws IOException {
            Directory directory = FSDirectory.open(Paths.get("/tmp/test/lucene"));
            IndexWriterConfig config = new IndexWriterConfig(analyzer);
            IndexWriter iwriter = new IndexWriter(directory, config);
            FieldType fieldType = new FieldType();
            fieldType.setStored(true);
            fieldType.setIndexOptions(IndexOptions.DOCS_AND_FREQS_AND_POSITIONS_AND_OFFSETS);
            Field idField = new Field("_id", id, fieldType);
            Document doc = new Document();
            doc.add(idField);
            iwriter.addDocument(doc);
            iwriter.close();
    
        }
    
        public static void query(String id) throws ParseException, IOException {
            Query query = new QueryParser("_id", analyzer).parse(id);
            Directory directory = FSDirectory.open(Paths.get("/tmp/test/lucene"));
            IndexReader ireader  = DirectoryReader.open(directory);
            IndexSearcher isearcher = new IndexSearcher(ireader);
            ScoreDoc[] scoreDoc = isearcher.search(query, 100).scoreDocs;
            for(ScoreDoc scdoc: scoreDoc){
                Document doc = isearcher.doc(scdoc.doc);
                System.out.println(doc.get("_id"));
            }
        }
    
        public static void delete(String id){
            try {
                 Directory directory = FSDirectory.open(Paths.get("/tmp/test/lucene"));
                IndexWriterConfig config = new IndexWriterConfig(analyzer);
                IndexWriter iwriter = new IndexWriter(directory, config);
                Term term = new Term("_id", id);
                iwriter.deleteDocuments(term);
                iwriter.commit();
                iwriter.close();
            }catch (IOException e){
                e.printStackTrace();
            }
        }
    }
    

    首先generateIndex()将在/tmp/test/lucene中生成索引,query()将显示id将成功查询,然后delete()希望删除文档,但query()将再次证明删除操作失败。

    以下是有人可能需要进行测试的pom依赖

        <dependency>
            <groupId>org.apache.lucene</groupId>
            <artifactId>lucene-core</artifactId>
            <version>5.5.4</version>
            <type>jar</type>
        </dependency>
        <dependency>
            <groupId>org.apache.lucene</groupId>
            <artifactId>lucene-analyzers-common</artifactId>
            <version>5.5.4</version>
        </dependency>
        <dependency>
            <groupId>org.apache.lucene</groupId>
            <artifactId>lucene-queryparser</artifactId>
            <version>5.5.4</version>
        </dependency>
        <dependency>
            <groupId>org.apache.lucene</groupId>
            <artifactId>lucene-analyzers-smartcn</artifactId>
            <version>5.5.4</version>
        </dependency>
    

    迫切希望得到答案。

1 个答案:

答案 0 :(得分:1)

您的问题出在分析仪上。 SimpleAnalyzer将标记定义为字母的最大字​​符串StandardAnalyzer,甚至WhitespaceAnalyzer,是更典型的选项),因此您要编制索引的值会被拆分为代币:&#34; b&#34;,&#34; a&#34;,&#34; b&#34;,&#34; d&#34;,&#34; f&#34;。您定义的删除方法虽然没有通过分析器,但只是创建一个原始术语。如果您尝试使用以下内容替换main,则可以看到此操作:

generateIndex("5836962b0293a47b09d345f1");
query("5836962b0293a47b09d345f1");
delete("b");
query("5836962b0293a47b09d345f1");

作为一般规则,查询和术语以及此类不会分析,QueryParser会这样做。

对于(看起来像什么)标识符字段,您可能根本不想分析此字段。在这种情况下,将其添加到FieldType:

fieldType.setTokenized(false);

然后,您必须更改查询(再次,QueryParser分析),然后使用TermQuery

Query query = new TermQuery(new Term("_id", id));