Lucene - 排序
在本章中，我们将研究 Lucene 默认给出搜索结果的排序顺序，或者可以根据需要进行操作的排序顺序。
按相关性排序
这是 Lucene 使用的默认排序模式。Lucene 按顶部最相关的点击提供结果。
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();
}
按索引顺序排序
Lucene 使用的就是这种排序模式。此处，第一个索引的文档首先显示在搜索结果中。
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();
}
应用示例
让我们创建一个测试 Lucene 应用程序来测试排序过程。
| 步 | 描述 |
|---|---|
| 1 | 按照Lucene - 第一个应用程序章节中的说明，在com.tutorialspoint.lucene包下创建一个名为LuceneFirstApplication的项目。您还可以使用在Lucene - 第一个应用程序章节中创建的项目来了解本章的搜索过程。 |
| 2 | 按照Lucene - 第一个应用程序章节中的说明创建LuceneConstants.java和Searcher.java。其余文件保持不变。 |
| 3 | 如下所述创建LuceneTester.java 。 |
| 4 | 清理并构建应用程序，以确保业务逻辑按照要求运行。 |
LuceneConstants.java
此类用于提供在示例应用程序中使用的各种常量。
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;
}
搜索器.java
该类用于读取对原始数据所做的索引并使用Lucene库搜索数据。
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
该类用于测试Lucene库的搜索能力。
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();
}
}
数据和索引目录创建
我们使用了从 record1.txt 到 record10.txt 的 10 个文本文件，其中包含学生的姓名和其他详细信息，并将它们放在目录E:\Lucene\Data 中。 测试数据。索引目录路径应创建为 E:\Lucene\Index。运行Lucene - 索引过程一章中的索引程序后，您可以看到在该文件夹中创建的索引文件列表。
运行程序
完成源、原始数据、数据目录、索引目录和索引的创建后，您就可以编译并运行程序了。为此，请保持LuceneTester.Java文件选项卡处于活动状态，并使用 Eclipse IDE 中提供的“运行”选项或使用Ctrl + F11编译并运行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 -
10 documents found. Time :31ms Score: 1.3179655 File: E:\Lucene\Data\record3.txt Score: 0.790779 File: E:\Lucene\Data\record1.txt Score: 0.790779 File: E:\Lucene\Data\record2.txt Score: 0.790779 File: E:\Lucene\Data\record4.txt Score: 0.790779 File: E:\Lucene\Data\record5.txt Score: 0.790779 File: E:\Lucene\Data\record6.txt Score: 0.790779 File: E:\Lucene\Data\record7.txt Score: 0.790779 File: E:\Lucene\Data\record8.txt Score: 0.790779 File: E:\Lucene\Data\record9.txt Score: 0.2635932 File: E:\Lucene\Data\record10.txt 10 documents found. Time :0ms Score: 0.790779 File: E:\Lucene\Data\record1.txt Score: 0.2635932 File: E:\Lucene\Data\record10.txt Score: 0.790779 File: E:\Lucene\Data\record2.txt Score: 1.3179655 File: E:\Lucene\Data\record3.txt Score: 0.790779 File: E:\Lucene\Data\record4.txt Score: 0.790779 File: E:\Lucene\Data\record5.txt Score: 0.790779 File: E:\Lucene\Data\record6.txt Score: 0.790779 File: E:\Lucene\Data\record7.txt Score: 0.790779 File: E:\Lucene\Data\record8.txt Score: 0.790779 File: E:\Lucene\Data\record9.txt