at.ac.univie.mminf.luceneSKOS.LabelbasedTermExpansionTest.java Source code

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Here is the source code for at.ac.univie.mminf.luceneSKOS.LabelbasedTermExpansionTest.java

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package at.ac.univie.mminf.luceneSKOS;

/**
 * Copyright 2010 Bernhard Haslhofer 
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.PerFieldAnalyzerWrapper;
import org.apache.lucene.analysis.SimpleAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.RAMDirectory;
import org.junit.Assert;
import org.junit.Test;

import at.ac.univie.mminf.luceneSKOS.analysis.SKOSAnalyzer;
import at.ac.univie.mminf.luceneSKOS.analysis.SKOSAnalyzer.ExpansionType;

/**
 * This test-case verifies and demonstrates the "Label-based term expansion" use
 * case as described in https://code.
 * google.com/p/lucene-skos/wiki/UseCases#UC2:_Label-based_term_expansion
 */
public class LabelbasedTermExpansionTest extends AbstractTermExpansionTest {

    /**
     * This test indexes a sample metadata record (=lucene document) having a
     * "title", "description", and "subject" field.
     * 
     * A search for "arms" returns that record as a result because "arms" is
     * defined as an alternative label for "weapons", the term which is contained
     * in the subject field.
     * 
     * @throws IOException
     */
    @Test
    public void labelBasedTermExpansion() throws IOException {

        /* defining the document to be indexed */
        Document doc = new Document();
        doc.add(new Field("title", "Spearhead", Field.Store.YES, Field.Index.ANALYZED));
        doc.add(new Field("description",
                "Roman iron spearhead. The spearhead was attached to one end of a wooden shaft..."
                        + "The spear was mainly a thrusting weapon, but could also be thrown. "
                        + "It was the principal weapon of the auxiliary soldier... "
                        + "(second - fourth century, Arbeia Roman Fort).",
                Field.Store.NO, Field.Index.ANALYZED));
        doc.add(new Field("subject", "weapons", Field.Store.NO, Field.Index.ANALYZED));

        /* setting up the SKOS analyzer */
        String skosFile = "src/test/resources/skos_samples/ukat_examples.n3";

        /* ExpansionType.URI->the field to be analyzed (expanded) contains URIs */
        Analyzer skosAnalyzer = new SKOSAnalyzer(matchVersion, skosFile, ExpansionType.LABEL);

        /* Define different analyzers for different fields */
        Map<String, Analyzer> analyzerPerField = new HashMap<String, Analyzer>();
        analyzerPerField.put("subject", skosAnalyzer);
        PerFieldAnalyzerWrapper indexAnalyzer = new PerFieldAnalyzerWrapper(new SimpleAnalyzer(matchVersion),
                analyzerPerField);

        /* setting up a writer with a default (simple) analyzer */
        writer = new IndexWriter(new RAMDirectory(), new IndexWriterConfig(matchVersion, indexAnalyzer));

        /* adding the document to the index */
        writer.addDocument(doc);

        /* defining a query that searches over all fields */
        BooleanQuery query1 = new BooleanQuery();
        query1.add(new TermQuery(new Term("title", "arms")), BooleanClause.Occur.SHOULD);
        query1.add(new TermQuery(new Term("description", "arms")), BooleanClause.Occur.SHOULD);
        query1.add(new TermQuery(new Term("subject", "arms")), BooleanClause.Occur.SHOULD);

        /* creating a new searcher */
        searcher = new IndexSearcher(IndexReader.open(writer, false));

        TopDocs results = searcher.search(query1, 10);

        /* the document matches because "arms" is among the expanded terms */
        Assert.assertEquals(1, results.totalHits);

        /* defining a query that searches for a broader concept */
        Query query2 = new TermQuery(new Term("subject", "military equipment"));

        results = searcher.search(query2, 10);

        /* ... also returns the document as result */
        Assert.assertEquals(1, results.totalHits);

    }

}