com.mathworks.xzheng.searching.ScoreTest.java Source code

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Here is the source code for com.mathworks.xzheng.searching.ScoreTest.java

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package com.mathworks.xzheng.searching;

/**
 * Copyright Manning Publications Co.
 *
 * 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 lan      
*/

import java.io.IOException;
import java.util.Vector;

import junit.framework.TestCase;

import org.apache.lucene.analysis.core.WhitespaceAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.AtomicReaderContext;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.FieldInvertState;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.CollectionStatistics;
import org.apache.lucene.search.Explanation;
import org.apache.lucene.search.FuzzyQuery;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.search.TermStatistics;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.search.WildcardQuery;
import org.apache.lucene.search.similarities.Similarity;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.RAMDirectory;
import org.apache.lucene.util.Version;

import com.mathworks.xzheng.meetlucene.Searcher;

// 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(DirectoryReader.open(directory));
        searcher.setSimilarity(new SimpleSimilarity());

        Query query = new TermQuery(new Term("contents", "x"));
        Explanation explanation = searcher.explain(query, 0);
        System.out.println(explanation);

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

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

    }

    private void indexSingleFieldDocs(Field[] fields) throws Exception {
        IndexWriterConfig config = new IndexWriterConfig(Version.LUCENE_46,
                new WhitespaceAnalyzer(Version.LUCENE_46));

        IndexWriter writer = new IndexWriter(directory, config);
        for (Field f : fields) {
            Document doc = new Document();
            doc.add(f);
            writer.addDocument(doc);
        }
        writer.forceMerge(1);
        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(DirectoryReader.open(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);

    }
    /*
      #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(DirectoryReader.open(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"));

    }

    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, Searcher searcher) {
            return 1.0f;
        }

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

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

        @Override
        public long computeNorm(FieldInvertState state) {
            // TODO Auto-generated method stub
            return 0;
        }

        @Override
        public SimWeight computeWeight(float queryBoost, CollectionStatistics collectionStats,
                TermStatistics... termStats) {
            // TODO Auto-generated method stub
            return null;
        }

        @Override
        public SimScorer simScorer(SimWeight weight, AtomicReaderContext context) throws IOException {
            // TODO Auto-generated method stub
            return null;
        }
    }

}