无法在Lucene 6.2中使用Scala进行搜索

Question

我正在尝试使用Lucene 6.2为MySQL中的数据（在Scala中使用Slick）编制索引。这里是下面的代码

package oc.api.services 

/** 
    * Created by sujit on 9/7/16. 
    */ 
import org.apache.lucene.document._ 
import org.apache.lucene.analysis.standard.StandardAnalyzer 
import org.apache.lucene.index._ 
import org.apache.lucene.search.IndexSearcher 
import java.io.{File, IOException} 
import java.nio.file.Paths 

import akka.actor.ActorSystem 
import akka.event.{Logging, LoggingAdapter} 
import akka.stream.ActorMaterializer 
import oc.api.utils.{Config, DatabaseService} 
import org.apache.lucene.analysis.core.KeywordAnalyzer 
import org.apache.lucene.index.IndexWriterConfig.OpenMode 
import org.apache.lucene.queryparser.classic.{QueryParser} 
import org.apache.lucene.store.FSDirectory 

import scala.concurrent.ExecutionContext 

class Indexer extends Config { 
    implicit val actorSystem = ActorSystem() 
    implicit val executor: ExecutionContext = actorSystem.dispatcher 
    implicit val log: LoggingAdapter = Logging(actorSystem, getClass) 
    implicit val materializer: ActorMaterializer = ActorMaterializer() 

    val databaseService = new DatabaseService(jdbcUrl, dbUser, dbPassword) 

    val notesService = new NotesService(databaseService)  

    def setIndex = { 
    val IndexStoreDir = Paths.get("/var/www/html/LuceneIndex") 
    val analyzer = new KeywordAnalyzer() 
    val writerConfig = new IndexWriterConfig(analyzer) 
    writerConfig.setOpenMode(OpenMode.CREATE) 
    writerConfig.setRAMBufferSizeMB(500) 
    val directory = FSDirectory.open(IndexStoreDir) 
    var writer = new IndexWriter(directory, writerConfig) 
    val notes = notesService.getNotes() //Gets all notes from slick. Data is coming in getNotes() 
    var doc = new Document() 
    var count = 0 

    val stringType = new FieldType() 
    notes.map(_.foreach{ 
     case(note) => 
     doc = new Document() 

     var field = new TextField("title", note.title, Field.Store.YES) 
     doc.add(field) 

     field = new TextField("teaser", note.teaser, Field.Store.YES) 
     doc.add(field) 

     field = new TextField("description", note.description, Field.Store.YES) 
     doc.add(field) 

     writer.addDocument(doc) 
    }) 
    writer.commit() 
    } 

    def search(keyword: String) = { 
    val IndexStoreDir = Paths.get("/var/www/html/LuceneIndex") 
    var directoryReader = DirectoryReader.open(FSDirectory.open(IndexStoreDir)) 
    val analyzer = new StandardAnalyzer() 

    val searcher = new IndexSearcher(directoryReader) 

    val mqp = new QueryParser("title", analyzer) //MultiFieldQueryParser(filesToSearch,analyzer) 
    val query = mqp.parse(keyword) 

    val hits = searcher.search(query,10) 
    val scoreDoc = hits.scoreDocs 
    println(scoreDoc.length) 
    } 

} 

object Indexer extends App { 
    val index = new Indexer 
    index.setIndex 
    index.search("Donec") 
} 

setIndex函数在提供的路径中按预期工作。但是当我根据关键字搜索索引时，它会抛出0结果。搜索功能有任何错误吗？这怎么解决？

Answer 1

这里的主要原因可能是您的分析仪不匹配。您使用KeywordAnalyzer进行索引编制，根本不分析。对于搜索，您使用StandardAnalyzer。在您的示例中，查询"Donec"将被解析并分析为title:donec，就好像您; d使用的是new TermQuery(new Term("title", "donec"))。由于您在索引时间使用了关键字分析器，因此这只会匹配确切标题为donec的文档。您应该尝试使用相同的分析器进行索引编制。

另一件事可能是 - 我只能猜测 - notesService.getNotes()可能是Future[_]（或类似的异步类型），因为它涉及光滑。如果是，则将呼叫中的所有文档添加到.map()，计划在未来解决后进行。但是，writer.commit()调用发生在调用线程中，可能在添加完所有文档之前，因此您应该将提交移动到map回调中。