在本章中,我们将研究Lucene默认提供的搜索结果排序顺序,或者根据需要进行操控。

按相关性排序

这是Lucene使用的默认排序模式。Lucene按照最相关的搜索结果排在顶部。

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private void sortUsingRelevance(String searchQuery) throws IOException, ParseException { searcher = new Searcher(indexDir); long startTime = System.currentTimeMillis(); // 创建用于搜索文件名的术语 Term term = new Term(LuceneConstants.FILE_NAME, searchQuery); // 创建术语查询对象 Query query = new FuzzyQuery(term); searcher.setDefaultFieldSortScoring(true, false); // 进行搜索 TopDocs hits = searcher.search(query, Sort.RELEVANCE); long endTime = System.currentTimeMillis(); System.out.println(hits.totalHits + " documents found. Time :" + (endTime - startTime) + "ms"); for(ScoreDoc scoreDoc : hits.scoreDocs) { Document doc = searcher.getDocument(scoreDoc); System.out.print("Score: "+ scoreDoc.score + " "); System.out.println("File: "+ doc.get(LuceneConstants.FILE_PATH)); } searcher.close(); }

按索引顺序排序

这种排序模式由Lucene使用。在这里,索引的第一个文档首先显示在搜索结果中。

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private void sortUsingIndex(String searchQuery) throws IOException, ParseException { searcher = new Searcher(indexDir); long startTime = System.currentTimeMillis(); // 创建用于搜索文件名的术语 Term term = new Term(LuceneConstants.FILE_NAME, searchQuery); // 创建术语查询对象 Query query = new FuzzyQuery(term); searcher.setDefaultFieldSortScoring(true, false); // 进行搜索 TopDocs hits = searcher.search(query, Sort.INDEXORDER); long endTime = System.currentTimeMillis(); System.out.println(hits.totalHits + " documents found. Time :" + (endTime - startTime) + "ms"); for(ScoreDoc scoreDoc : hits.scoreDocs) { Document doc = searcher.getDocument(scoreDoc); System.out.print("Score: "+ scoreDoc.score + " "); System.out.println("File: "+ doc.get(LuceneConstants.FILE_PATH)); } searcher.close(); }
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package com.tutorialspoint.lucene; import java.io.File; import java.io.IOException; import org.apache.lucene.analysis.standard.StandardAnalyzer; import org.apache.lucene.document.Document; import org.apache.lucene.index.CorruptIndexException; import org.apache.lucene.queryParser.ParseException; import org.apache.lucene.queryParser.QueryParser; import org.apache.lucene.search.IndexSearcher; import org.apache.lucene.search.Query; import org.apache.lucene.search.ScoreDoc; import org.apache.lucene.search.Sort; import org.apache.lucene.search.TopDocs; import org.apache.lucene.store.Directory; import org.apache.lucene.store.FSDirectory; import org.apache.lucene.util.Version; public class Searcher { IndexSearcher indexSearcher; QueryParser queryParser; Query query; public Searcher(String indexDirectoryPath) throws IOException { Directory indexDirectory = FSDirectory.open(new File(indexDirectoryPath)); indexSearcher = new IndexSearcher(indexDirectory); queryParser = new QueryParser(Version.LUCENE_36, LuceneConstants.CONTENTS, new StandardAnalyzer(Version.LUCENE_36)); } public TopDocs search(String searchQuery) throws IOException, ParseException { query = queryParser.parse(searchQuery); return indexSearcher.search(query, LuceneConstants.MAX_SEARCH); } public TopDocs search(Query query) throws IOException, ParseException { return indexSearcher.search(query, LuceneConstants.MAX_SEARCH); } public TopDocs search(Query query, Sort sort) throws IOException, ParseException { return indexSearcher.search(query, LuceneConstants.MAX_SEARCH, sort); } public void setDefaultFieldSortScoring(boolean doTrackScores, boolean doMaxScores) { indexSearcher.setDefaultFieldSortScoring( doTrackScores, doMaxScores); } public Document getDocument(ScoreDoc scoreDoc) throws CorruptIndexException, IOException { return indexSearcher.doc(scoreDoc.doc); } public void close() throws IOException { indexSearcher.close(); } }

以上是示例应用程序的Searcher类的实现,它用于读取原始数据上创建的索引,并使用Lucene库搜索数据。

示例应用程序

创建测试 Lucene 应用程序以测试排序过程

步骤描述

  1. 创建一个名为 LuceneFirstApplication 的项目,位于 com.tutorialspoint.lucene 包下,如《Lucene - First Application》章节所述。您也可以直接使用《Lucene - First Application》章节中创建的项目,以便在本章理解搜索过程。

  2. 如《Lucene - First Application》章节所述,创建 LuceneConstants.java 和 Searcher.java。保持其他文件不变。

  3. 如下所述,创建 LuceneTester.java。

  4. 清理并构建应用程序,以确保业务逻辑符合要求。

LuceneConstants.java

该类用于提供在示例应用程序中使用的各种常量。

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package com.tutorialspoint.lucene; public class LuceneConstants { public static final String CONTENTS = "contents"; public static final String FILE_NAME = "filename"; public static final String FILE_PATH = "filepath"; public static final int MAX_SEARCH = 10; }

Searcher.java

Searcher.java 类用于读取在原始数据上创建的索引,并利用 Lucene 库搜索数据。

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package com.tutorialspoint.lucene; import java.io.File; import java.io.IOException; import org.apache.lucene.analysis.standard.StandardAnalyzer; import org.apache.lucene.document.Document; import org.apache.lucene.index.CorruptIndexException; import org.apache.lucene.queryParser.ParseException; import org.apache.lucene.queryParser.QueryParser; import org.apache.lucene.search.IndexSearcher; import org.apache.lucene.search.Query; import org.apache.lucene.search.ScoreDoc; import org.apache.lucene.search.Sort; import org.apache.lucene.search.TopDocs; import org.apache.lucene.store.Directory; import org.apache.lucene.store.FSDirectory; import org.apache.lucene.util.Version; public class Searcher { IndexSearcher indexSearcher; QueryParser queryParser; Query query; public Searcher(String indexDirectoryPath) throws IOException { Directory indexDirectory = FSDirectory.open(new File(indexDirectoryPath)); indexSearcher = new IndexSearcher(indexDirectory); queryParser = new QueryParser(Version.LUCENE_36, LuceneConstants.CONTENTS, new StandardAnalyzer(Version.LUCENE_36)); } public TopDocs search( String searchQuery) throws IOException, ParseException { query = queryParser.parse(searchQuery); return indexSearcher.search(query, LuceneConstants.MAX_SEARCH); } public TopDocs search(Query query) throws IOException, ParseException { return indexSearcher.search(query, LuceneConstants.MAX_SEARCH); } public TopDocs search(Query query,Sort sort) throws IOException, ParseException { return indexSearcher.search(query, LuceneConstants.MAX_SEARCH,sort); } public void setDefaultFieldSortScoring(boolean doTrackScores, boolean doMaxScores) { indexSearcher.setDefaultFieldSortScoring( doTrackScores,doMaxScores); } public Document getDocument(ScoreDoc scoreDoc) throws CorruptIndexException, IOException { return indexSearcher.doc(scoreDoc.doc); } public void close() throws IOException { indexSearcher.close(); } }

LuceneTester.java

LuceneTester.java 类用于测试 Lucene 库的搜索功能。

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package com.tutorialspoint.lucene; import java.io.IOException; import org.apache.lucene.document.Document; import org.apache.lucene.index.Term; import org.apache.lucene.queryParser.ParseException; import org.apache.lucene.search.FuzzyQuery; import org.apache.lucene.search.Query; import org.apache.lucene.search.ScoreDoc; import org.apache.lucene.search.Sort; import org.apache.lucene.search.TopDocs; public class LuceneTester { String indexDir = "E:\\Lucene\\Index"; String dataDir = "E:\\Lucene\\Data"; Indexer indexer; Searcher searcher; public static void main(String[] args) { LuceneTester tester; try { tester = new LuceneTester(); tester.sortUsingRelevance("cord3.txt"); tester.sortUsingIndex("cord3.txt"); } catch (IOException e) { e.printStackTrace(); } catch (ParseException e) { e.printStackTrace(); } } private void sortUsingRelevance(String searchQuery) throws IOException, ParseException { searcher = new Searcher(indexDir); long startTime = System.currentTimeMillis(); //create a term to search file name Term term = new Term(LuceneConstants.FILE_NAME, searchQuery); //create the term query object Query query = new FuzzyQuery(term); searcher.setDefaultFieldSortScoring(true, false); //do the search TopDocs hits = searcher.search(query,Sort.RELEVANCE); long endTime = System.currentTimeMillis(); System.out.println(hits.totalHits + " documents found. Time :" + (endTime - startTime) + "ms"); for(ScoreDoc scoreDoc : hits.scoreDocs) { Document doc = searcher.getDocument(scoreDoc); System.out.print("Score: "+ scoreDoc.score + " "); System.out.println("File: "+ doc.get(LuceneConstants.FILE_PATH)); } searcher.close(); } private void sortUsingIndex(String searchQuery) throws IOException, ParseException { searcher = new Searcher(indexDir); long startTime = System.currentTimeMillis(); //create a term to search file name Term term = new Term(LuceneConstants.FILE_NAME, searchQuery); //create the term query object Query query = new FuzzyQuery(term); searcher.setDefaultFieldSortScoring(true, false); //do the search TopDocs hits = searcher.search(query,Sort.INDEXORDER); long endTime = System.currentTimeMillis(); System.out.println(hits.totalHits + " documents found. Time :" + (endTime - startTime) + "ms"); for(ScoreDoc scoreDoc : hits.scoreDocs) { Document doc = searcher.getDocument(scoreDoc); System.out.print("Score: "+ scoreDoc.score + " "); System.out.println("File: "+ doc.get(LuceneConstants.FILE_PATH)); } searcher.close(); } }

数据与索引目录创建

概述

我们使用了从 record1.txt 到 record10.txt 的 10 个文本文件,这些文件包含了学生的姓名和其他详细信息,并将它们放置在目录 E:\Lucene\Data 中。测试数据。索引目录路径应该创建为 E:\Lucene\Index。在运行章节 Lucene - Indexing Process 中的索引程序后,您可以在该文件夹中看到创建的索引文件列表。

程序运行

一旦您完成了源代码、原始数据、数据目录、索引目录以及索引的创建,您就可以编译并运行您的程序。要做到这一点,保持 LuceneTester.java 文件选项卡处于活动状态,并在 Eclipse IDE 中使用“运行”选项,或使用 Ctrl + F11 编译并运行您的 LuceneTester 应用程序。如果您的应用程序成功运行,它将在 Eclipse IDE 的控制台中打印以下消息:

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找到 10 个文档。时间:31ms 得分:1.3179655 文件:E:\Lucene\Data\record3.txt 得分:0.790779 文件:E:\Lucene\Data\record1.txt 得分:0.790779 文件:E:\Lucene\Data\record2.txt 得分:0.790779 文件:E:\Lucene\Data\record4.txt 得分:0.790779 文件:E:\Lucene\Data\record5.txt 得分:0.790779 文件:E:\Lucene\Data\record6.txt 得分:0.790779 文件:E:\Lucene\Data\record7.txt 得分:0.790779 文件:E:\Lucene\Data\record8.txt 得分:0.790779 文件:E:\Lucene\Data\record9.txt 得分:0.2635932 文件:E:\Lucene\Data\record10.txt 找到 10 个文档。时间:0ms 得分:0.790779 文件:E:\Lucene\Data\record1.txt 得分:0.2635932 文件:E:\Lucene\Data\record10.txt 得分:0.790779 文件:E:\Lucene\Data\record2.txt 得分:1.3179655 文件:E:\Lucene\Data\record3.txt 得分:0.790779 文件:E:\Lucene\Data\record4.txt 得分:0.790779 文件:E:\Lucene\Data\record5.txt 得分:0.790779 文件:E:\Lucene\Data\record6.txt 得分:0.790779 文件:E:\Lucene\Data\record7.txt 得分:0.790779 文件:E:\Lucene\Data\record8.txt 得分:0.790779 文件:E:\Lucene\Data\record9.txt

注意事项

  • 在执行程序之前,请确保已正确设置 Lucene 库。

  • 请确保提供了正确的原始数据和索引目录路径。

  • 请根据需要修改程序以适应您的环境。

参考资料

https://www.tutorialspoint.com/lucene/lucene_sorting.htm