aos.lucene.search.msc.ScoreTest.java Source code

Introduction

Here is the source code for aos.lucene.search.msc.ScoreTest.java

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package aos.lucene.search.msc;

import junit.framework.TestCase;

import org.apache.lucene.analysis.WhitespaceAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.Explanation;
import org.apache.lucene.search.FuzzyQuery;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.Searcher;
import org.apache.lucene.search.Similarity;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.search.WildcardQuery;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.RAMDirectory;

import java.util.Vector;

// From chapter 3
public class ScoreTest extends TestCase {
    private Directory directory;

    public void setUp() throws Exception {
        directory = new RAMDirectory();
    }

    public void tearDown() throws Exception {
        directory.close();
    }

    public void testSimple() throws Exception {
        indexSingleFieldDocs(new Field[] { new Field("contents", "x", Field.Store.YES, Field.Index.ANALYZED) });
        IndexSearcher searcher = new IndexSearcher(directory);
        searcher.setSimilarity(new SimpleSimilarity());

        Query query = new TermQuery(new Term("contents", "x"));
        Explanation explanation = searcher.explain(query, 0);
        LOGGER.info(explanation);

        TopDocs matches = searcher.search(query, 10);
        assertEquals(1, matches.totalHits);

        assertEquals(1F, matches.scoreDocs[0].score, 0.0);

        searcher.close();
    }

    private void indexSingleFieldDocs(Field[] fields) throws Exception {
        IndexWriter writer = new IndexWriter(directory, new WhitespaceAnalyzer(Version.LUCENE_46),
                IndexWriter.MaxFieldLength.UNLIMITED);
        for (Field f : fields) {
            Document doc = new Document();
            doc.add(f);
            writer.addDocument(doc);
        }
        writer.merge(writer.getNextMerge());
        writer.close();
    }

    public void testWildcard() throws Exception {
        indexSingleFieldDocs(new Field[] { new Field("contents", "wild", Field.Store.YES, Field.Index.ANALYZED),
                new Field("contents", "child", Field.Store.YES, Field.Index.ANALYZED),
                new Field("contents", "mild", Field.Store.YES, Field.Index.ANALYZED),
                new Field("contents", "mildew", Field.Store.YES, Field.Index.ANALYZED) });

        IndexSearcher searcher = new IndexSearcher(directory);
        Query query = new WildcardQuery(new Term("contents", "?ild*")); //#A
        TopDocs matches = searcher.search(query, 10);
        assertEquals("child no match", 3, matches.totalHits);

        assertEquals("score the same", matches.scoreDocs[0].score, matches.scoreDocs[1].score, 0.0);
        assertEquals("score the same", matches.scoreDocs[1].score, matches.scoreDocs[2].score, 0.0);
        searcher.close();
    }
    /*
      #A Construct WildcardQuery using Term
    */

    public void testFuzzy() throws Exception {
        indexSingleFieldDocs(new Field[] { new Field("contents", "fuzzy", Field.Store.YES, Field.Index.ANALYZED),
                new Field("contents", "wuzzy", Field.Store.YES, Field.Index.ANALYZED) });

        IndexSearcher searcher = new IndexSearcher(directory);
        Query query = new FuzzyQuery(new Term("contents", "wuzza"));
        TopDocs matches = searcher.search(query, 10);
        assertEquals("both close enough", 2, matches.totalHits);

        assertTrue("wuzzy closer than fuzzy", matches.scoreDocs[0].score != matches.scoreDocs[1].score);

        Document doc = searcher.doc(matches.scoreDocs[0].doc);
        assertEquals("wuzza bear", "wuzzy", doc.get("contents"));
        searcher.close();
    }

    public static class SimpleSimilarity extends Similarity {
        public float lengthNorm(String field, int numTerms) {
            return 1.0f;
        }

        public float queryNorm(float sumOfSquaredWeights) {
            return 1.0f;
        }

        public float tf(float freq) {
            return freq;
        }

        public float sloppyFreq(int distance) {
            return 2.0f;
        }

        public float idf(Vector terms, SimpleSearcher searcher) {
            return 1.0f;
        }

        public float idf(int docFreq, int numDocs) {
            return 1.0f;
        }

        public float coord(int overlap, int maxOverlap) {
            return 1.0f;
        }
    }

}