package org.apache.lucene.analysis.core;
/**
* Copyright 2005 The Apache Software Foundation
*
* 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.io.Reader;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.Set;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.BaseTokenStreamTestCase;
import org.apache.lucene.analysis.MockTokenizer;
import org.apache.lucene.analysis.TokenFilter;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.Tokenizer;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
import org.apache.lucene.analysis.tokenattributes.PositionIncrementAttribute;
import org.apache.lucene.analysis.util.CharArraySet;
import org.apache.lucene.util.English;
import org.apache.lucene.util.Version;
public class TestStopFilter extends BaseTokenStreamTestCase {
// other StopFilter functionality is already tested by TestStopAnalyzer
public void testExactCase() throws IOException {
StringReader reader = new StringReader("Now is The Time");
CharArraySet stopWords = new CharArraySet(TEST_VERSION_CURRENT, asSet("is", "the", "Time"), false);
TokenStream stream = new StopFilter(TEST_VERSION_CURRENT, new MockTokenizer(reader, MockTokenizer.WHITESPACE, false), stopWords);
assertTokenStreamContents(stream, new String[] { "Now", "The" });
}
public void testStopFilt() throws IOException {
StringReader reader = new StringReader("Now is The Time");
String[] stopWords = new String[] { "is", "the", "Time" };
CharArraySet stopSet = StopFilter.makeStopSet(TEST_VERSION_CURRENT, stopWords);
TokenStream stream = new StopFilter(TEST_VERSION_CURRENT, new MockTokenizer(reader, MockTokenizer.WHITESPACE, false), stopSet);
assertTokenStreamContents(stream, new String[] { "Now", "The" });
}
/**
* Test Position increments applied by StopFilter with and without enabling this option.
*/
public void testStopPositons() throws IOException {
StringBuilder sb = new StringBuilder();
ArrayList<String> a = new ArrayList<String>();
for (int i=0; i<20; i++) {
String w = English.intToEnglish(i).trim();
sb.append(w).append(" ");
if (i%3 != 0) a.add(w);
}
log(sb.toString());
String stopWords[] = a.toArray(new String[0]);
for (int i=0; i<a.size(); i++) log("Stop: "+stopWords[i]);
CharArraySet stopSet = StopFilter.makeStopSet(TEST_VERSION_CURRENT, stopWords);
// with increments
StringReader reader = new StringReader(sb.toString());
StopFilter stpf = new StopFilter(Version.LUCENE_40, new MockTokenizer(reader, MockTokenizer.WHITESPACE, false), stopSet);
doTestStopPositons(stpf,true);
// without increments
reader = new StringReader(sb.toString());
stpf = new StopFilter(Version.LUCENE_43, new MockTokenizer(reader, MockTokenizer.WHITESPACE, false), stopSet);
doTestStopPositons(stpf,false);
// with increments, concatenating two stop filters
ArrayList<String> a0 = new ArrayList<String>();
ArrayList<String> a1 = new ArrayList<String>();
for (int i=0; i<a.size(); i++) {
if (i%2==0) {
a0.add(a.get(i));
} else {
a1.add(a.get(i));
}
}
String stopWords0[] = a0.toArray(new String[0]);
for (int i=0; i<a0.size(); i++) log("Stop0: "+stopWords0[i]);
String stopWords1[] = a1.toArray(new String[0]);
for (int i=0; i<a1.size(); i++) log("Stop1: "+stopWords1[i]);
CharArraySet stopSet0 = StopFilter.makeStopSet(TEST_VERSION_CURRENT, stopWords0);
CharArraySet stopSet1 = StopFilter.makeStopSet(TEST_VERSION_CURRENT, stopWords1);
reader = new StringReader(sb.toString());
StopFilter stpf0 = new StopFilter(TEST_VERSION_CURRENT, new MockTokenizer(reader, MockTokenizer.WHITESPACE, false), stopSet0); // first part of the set
stpf0.setEnablePositionIncrements(true);
StopFilter stpf01 = new StopFilter(TEST_VERSION_CURRENT, stpf0, stopSet1); // two stop filters concatenated!
doTestStopPositons(stpf01,true);
}
// LUCENE-3849: make sure after .end() we see the "ending" posInc
public void testEndStopword() throws Exception {
CharArraySet stopSet = StopFilter.makeStopSet(TEST_VERSION_CURRENT, "of");
StopFilter stpf = new StopFilter(Version.LUCENE_40, new MockTokenizer(new StringReader("test of"), MockTokenizer.WHITESPACE, false), stopSet);
assertTokenStreamContents(stpf, new String[] { "test" },
new int[] {0},
new int[] {4},
null,
new int[] {1},
null,
7,
1,
null,
true);
}
private void doTestStopPositons(StopFilter stpf, boolean enableIcrements) throws IOException {
log("---> test with enable-increments-"+(enableIcrements?"enabled":"disabled"));
stpf.setEnablePositionIncrements(enableIcrements);
CharTermAttribute termAtt = stpf.getAttribute(CharTermAttribute.class);
PositionIncrementAttribute posIncrAtt = stpf.getAttribute(PositionIncrementAttribute.class);
stpf.reset();
for (int i=0; i<20; i+=3) {
assertTrue(stpf.incrementToken());
log("Token "+i+": "+stpf);
String w = English.intToEnglish(i).trim();
assertEquals("expecting token "+i+" to be "+w,w,termAtt.toString());
assertEquals("all but first token must have position increment of 3",enableIcrements?(i==0?1:3):1,posIncrAtt.getPositionIncrement());
}
assertFalse(stpf.incrementToken());
stpf.end();
stpf.close();
}
// print debug info depending on VERBOSE
private static void log(String s) {
if (VERBOSE) {
System.out.println(s);
}
}
// stupid filter that inserts synonym of 'hte' for 'the'
private class MockSynonymFilter extends TokenFilter {
State bufferedState;
CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
PositionIncrementAttribute posIncAtt = addAttribute(PositionIncrementAttribute.class);
MockSynonymFilter(TokenStream input) {
super(input);
}
@Override
public boolean incrementToken() throws IOException {
if (bufferedState != null) {
restoreState(bufferedState);
posIncAtt.setPositionIncrement(0);
termAtt.setEmpty().append("hte");
bufferedState = null;
return true;
} else if (input.incrementToken()) {
if (termAtt.toString().equals("the")) {
bufferedState = captureState();
}
return true;
} else {
return false;
}
}
@Override
public void reset() throws IOException {
super.reset();
bufferedState = null;
}
}
public void testFirstPosInc() throws Exception {
Analyzer analyzer = new Analyzer() {
@Override
protected TokenStreamComponents createComponents(String fieldName, Reader reader) {
Tokenizer tokenizer = new MockTokenizer(reader, MockTokenizer.WHITESPACE, false);
TokenFilter filter = new MockSynonymFilter(tokenizer);
StopFilter stopfilter = new StopFilter(Version.LUCENE_43, filter, StopAnalyzer.ENGLISH_STOP_WORDS_SET);
stopfilter.setEnablePositionIncrements(false);
return new TokenStreamComponents(tokenizer, stopfilter);
}
};
assertAnalyzesTo(analyzer, "the quick brown fox",
new String[] { "hte", "quick", "brown", "fox" },
new int[] { 1, 1, 1, 1} );
}
}