Lucene - TermRangeQuery



TermRangeQuery is used when a range of textual terms are to be searched.

Class Declaration

Following is the declaration for the org.apache.lucene.search.TermRangeQuery class −

public class TermRangeQuery
   extends MultiTermQuery

Class Constructors

The following table shows the different class constructors −

S.No. Constructor & Description
1

TermRangeQuery(String field, String lowerTerm, String upperTerm, boolean includeLower, boolean includeUpper)

Constructs a queryselecting all terms greater/equal than lowerTerm but less/equal than upperTerm.

2

TermRangeQuery(String field, String lowerTerm, String upperTerm, boolean includeLower, boolean includeUpper, Collator collator)

Constructs a query selecting all terms greater/equal than lowerTerm but less/equal than upperTerm.

Class Methods

The following table shows the different class methods −

S.No. Method & Description
1

boolean equals(Object obj)

2

Collator getCollator()

Returns the collator used to determine range inclusion, if any.

3

protected FilteredTermEnum getEnum(IndexReader reader)

Construct the enumeration to be used, expanding the pattern term.

4

String getField()

Returns the field name for this query.

5

String getLowerTerm()

Returns the lower value of this range query

6

String getUpperTerm()

Returns the upper value of this range query.

7

int hashCode()

8

boolean includesLower()

Returns true if the lower endpoint is inclusive.

9

boolean includesUpper()

Returns true if the upper endpoint is inclusive.

10

String toString(String field)

Prints a user-readable version of this query.

Methods Inherited

This class inherits methods from the following classes −

  • org.apache.lucene.search.MultiTermQuery
  • org.apache.lucene.search.Query
  • java.lang.Object

Usage

private void searchUsingTermRangeQuery(String searchQueryMin,
   String searchQueryMax)throws IOException, ParseException {
   searcher = new Searcher(indexDir);
   long startTime = System.currentTimeMillis();
   
   //create the term query object
   Query query = new TermRangeQuery(LuceneConstants.FILE_NAME, 
      searchQueryMin,searchQueryMax,true,false);
   //do the search
   TopDocs hits = searcher.search(query);
   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.println("File: "+ doc.get(LuceneConstants.FILE_PATH));
   }
   searcher.close();
}

Example Application

Let us create a test Lucene application to test search using TermRangeQuery.

Step Description
1

Create a project with a name LuceneFirstApplication under a package com.tutorialspoint.lucene as explained in the Lucene - First Application chapter. You can also use the project created in Lucene - First Application chapter as such for this chapter to understand the searching process.

2

Create LuceneConstants.java and Searcher.java as explained in the Lucene - First Application chapter. Keep the rest of the files unchanged.

3

Create LuceneTester.java as mentioned below.

4

Clean and Build the application to make sure business logic is working as per the requirements.

LuceneConstants.java

This class is used to provide various constants to be used across the sample application.

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

This class is used to read the indexes made on raw data and searches data using the Lucene library.

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.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 Document getDocument(ScoreDoc scoreDoc) 
      throws CorruptIndexException, IOException {
     return indexSearcher.doc(scoreDoc.doc);	
   }

   public void close() throws IOException {
      indexSearcher.close();
   }
}

LuceneTester.java

This class is used to test the searching capability of the Lucene library.

package com.tutorialspoint.lucene;

import java.io.IOException;

import org.apache.lucene.document.Document;
import org.apache.lucene.queryParser.ParseException;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.TermRangeQuery;
import org.apache.lucene.search.TopDocs;

public class LuceneTester {
	
   String indexDir = "E:\\Lucene\\Index";
   String dataDir = "E:\\Lucene\\Data";
   Searcher searcher;

   public static void main(String[] args) {
      LuceneTester tester;
      try {
         tester = new LuceneTester();
         tester.searchUsingTermRangeQuery("record2.txt","record6.txt");
      } catch (IOException e) {
         e.printStackTrace();
      } catch (ParseException e) {
         e.printStackTrace();
      }
   }

   private void searchUsingTermRangeQuery(String searchQueryMin,
      String searchQueryMax)throws IOException, ParseException {
      searcher = new Searcher(indexDir);
      long startTime = System.currentTimeMillis();
      
      //create the term query object
      Query query = new TermRangeQuery(LuceneConstants.FILE_NAME, 
         searchQueryMin,searchQueryMax,true,false);
      //do the search
      TopDocs hits = searcher.search(query);
      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.println("File: "+ doc.get(LuceneConstants.FILE_PATH));
      }
      searcher.close();
   }
}

Data & Index Directory Creation

We have used 10 text files from record1.txt to record10.txt containing names and other details of the students and put them in the directory E:\Lucene\Data. Test Data. An index directory path should be created as E:\Lucene\Index. After running the indexing program in the chapter Lucene - Indexing Process, you can see the list of index files created in that folder.

Running the Program

Once you are done with the creation of the source, the raw data, the data directory, the index directory and the indexes, you can proceed by compiling and running your program. To do this, keep the LuceneTester.Java file tab active and use either the Run option available in the Eclipse IDE or use Ctrl + F11 to compile and run your LuceneTester application. If your application runs successfully, it will print the following message in Eclipse IDE's console −

4 documents found. Time :17ms
File: E:\Lucene\Data\record2.txt
File: E:\Lucene\Data\record3.txt
File: E:\Lucene\Data\record4.txt
File: E:\Lucene\Data\record5.txt
lucene_query_programming.htm
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