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Lucene example source code file (QueryAutoStopWordAnalyzerTest.java)

This example Lucene source code file (QueryAutoStopWordAnalyzerTest.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Lucene tags/keywords

a, a, exception, exception, field, indexwriter, io, mockanalyzer, mocktokenizer, override, queryautostopwordanalyzer, queryautostopwordanalyzer, should, string, string

The Lucene QueryAutoStopWordAnalyzerTest.java source code

package org.apache.lucene.analysis.query;
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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,
 * See the License for the specific language governing permissions and
 * limitations under the License.

import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.BaseTokenStreamTestCase;
import org.apache.lucene.analysis.MockAnalyzer;
import org.apache.lucene.analysis.MockTokenizer;
import org.apache.lucene.analysis.TokenStream;
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.queryParser.ParseException;
import org.apache.lucene.queryParser.QueryParser;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.store.RAMDirectory;

public class QueryAutoStopWordAnalyzerTest extends BaseTokenStreamTestCase {
  String variedFieldValues[] = {"the", "quick", "brown", "fox", "jumped", "over", "the", "lazy", "boring", "dog"};
  String repetitiveFieldValues[] = {"boring", "boring", "vaguelyboring"};
  RAMDirectory dir;
  Analyzer appAnalyzer;
  IndexReader reader;
  QueryAutoStopWordAnalyzer protectedAnalyzer;

  public void setUp() throws Exception {
    dir = new RAMDirectory();
    appAnalyzer = new MockAnalyzer(random, MockTokenizer.WHITESPACE, false);
    IndexWriter writer = new IndexWriter(dir, new IndexWriterConfig(TEST_VERSION_CURRENT, appAnalyzer));
    int numDocs = 200;
    for (int i = 0; i < numDocs; i++) {
      Document doc = new Document();
      String variedFieldValue = variedFieldValues[i % variedFieldValues.length];
      String repetitiveFieldValue = repetitiveFieldValues[i % repetitiveFieldValues.length];
      doc.add(new Field("variedField", variedFieldValue, Field.Store.YES, Field.Index.ANALYZED));
      doc.add(new Field("repetitiveField", repetitiveFieldValue, Field.Store.YES, Field.Index.ANALYZED));
    reader = IndexReader.open(dir, true);
    protectedAnalyzer = new QueryAutoStopWordAnalyzer(TEST_VERSION_CURRENT, appAnalyzer);

  public void tearDown() throws Exception {

  //Helper method to query
  private int search(Analyzer a, String queryString) throws IOException, ParseException {
    QueryParser qp = new QueryParser(TEST_VERSION_CURRENT, "repetitiveField", a);
    Query q = qp.parse(queryString);
    IndexSearcher searcher = newSearcher(reader);
    int hits = searcher.search(q, null, 1000).totalHits;
    return hits;

  public void testUninitializedAnalyzer() throws Exception {
    //Note: no calls to "addStopWord"
    String query = "variedField:quick repetitiveField:boring";
    int numHits1 = search(protectedAnalyzer, query);
    int numHits2 = search(appAnalyzer, query);
    assertEquals("No filtering test", numHits1, numHits2);

    * Test method for 'org.apache.lucene.analysis.QueryAutoStopWordAnalyzer.addStopWords(IndexReader)'
  public void testDefaultAddStopWordsIndexReader() throws Exception {
    int numHits = search(protectedAnalyzer, "repetitiveField:boring");
    assertEquals("Default filter should remove all docs", 0, numHits);

    * Test method for 'org.apache.lucene.analysis.QueryAutoStopWordAnalyzer.addStopWords(IndexReader, int)'
  public void testAddStopWordsIndexReaderInt() throws Exception {
    protectedAnalyzer.addStopWords(reader, 1f / 2f);
    int numHits = search(protectedAnalyzer, "repetitiveField:boring");
    assertEquals("A filter on terms in > one half of docs remove boring docs", 0, numHits);

    numHits = search(protectedAnalyzer, "repetitiveField:vaguelyboring");
    assertTrue("A filter on terms in > half of docs should not remove vaguelyBoring docs", numHits > 1);

    protectedAnalyzer.addStopWords(reader, 1f / 4f);
    numHits = search(protectedAnalyzer, "repetitiveField:vaguelyboring");
    assertEquals("A filter on terms in > quarter of docs should remove vaguelyBoring docs", 0, numHits);

  public void testAddStopWordsIndexReaderStringFloat() throws Exception {
    protectedAnalyzer.addStopWords(reader, "variedField", 1f / 2f);
    int numHits = search(protectedAnalyzer, "repetitiveField:boring");
    assertTrue("A filter on one Field should not affect queris on another", numHits > 0);

    protectedAnalyzer.addStopWords(reader, "repetitiveField", 1f / 2f);
    numHits = search(protectedAnalyzer, "repetitiveField:boring");
    assertEquals("A filter on the right Field should affect queries on it", numHits, 0);

  public void testAddStopWordsIndexReaderStringInt() throws Exception {
    int numStopWords = protectedAnalyzer.addStopWords(reader, "repetitiveField", 10);
    assertTrue("Should have identified stop words", numStopWords > 0);

    Term[] t = protectedAnalyzer.getStopWords();
    assertEquals("num terms should = num stopwords returned", t.length, numStopWords);

    int numNewStopWords = protectedAnalyzer.addStopWords(reader, "variedField", 10);
    assertTrue("Should have identified more stop words", numNewStopWords > 0);
    t = protectedAnalyzer.getStopWords();
    assertEquals("num terms should = num stopwords returned", t.length, numStopWords + numNewStopWords);

  public void testNoFieldNamePollution() throws Exception {
    protectedAnalyzer.addStopWords(reader, "repetitiveField", 10);
    int numHits = search(protectedAnalyzer, "repetitiveField:boring");
    assertEquals("Check filter set up OK", 0, numHits);

    numHits = search(protectedAnalyzer, "variedField:boring");
    assertTrue("Filter should not prevent stopwords in one field being used in another ", numHits > 0);

   * analyzer that does not support reuse
   * it is LetterTokenizer on odd invocations, WhitespaceTokenizer on even.
  private class NonreusableAnalyzer extends Analyzer {
    int invocationCount = 0;
    public TokenStream tokenStream(String fieldName, Reader reader) {
      if (++invocationCount % 2 == 0)
        return new MockTokenizer(reader, MockTokenizer.WHITESPACE, false);
        return new MockTokenizer(reader, MockTokenizer.SIMPLE, false);
  public void testWrappingNonReusableAnalyzer() throws Exception {
    QueryAutoStopWordAnalyzer a = new QueryAutoStopWordAnalyzer(TEST_VERSION_CURRENT, new NonreusableAnalyzer());
    a.addStopWords(reader, 10);
    int numHits = search(a, "repetitiveField:boring");
    assertTrue(numHits == 0);
    numHits = search(a, "repetitiveField:vaguelyboring");
    assertTrue(numHits == 0);
  public void testTokenStream() throws Exception {
    QueryAutoStopWordAnalyzer a = new QueryAutoStopWordAnalyzer(TEST_VERSION_CURRENT, new MockAnalyzer(random, MockTokenizer.WHITESPACE, false));
    a.addStopWords(reader, 10);
    TokenStream ts = a.tokenStream("repetitiveField", new StringReader("this boring"));
    assertTokenStreamContents(ts, new String[] { "this" });

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