package org.apache.lucene.analysis.de;
/*
* 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,
* 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.InputStream;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.BaseTokenStreamTestCase;
import org.apache.lucene.analysis.MockTokenizer;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.Tokenizer;
import org.apache.lucene.analysis.core.KeywordTokenizer;
import org.apache.lucene.analysis.core.LowerCaseFilter;
import org.apache.lucene.analysis.miscellaneous.SetKeywordMarkerFilter;
import org.apache.lucene.analysis.util.CharArraySet;
import static org.apache.lucene.analysis.VocabularyAssert.*;
/**
* Test the German stemmer. The stemming algorithm is known to work less
* than perfect, as it doesn't use any word lists with exceptions. We
* also check some of the cases where the algorithm is wrong.
*
*/
public class TestGermanStemFilter extends BaseTokenStreamTestCase {
Analyzer analyzer = new Analyzer() {
@Override
protected TokenStreamComponents createComponents(String fieldName) {
Tokenizer t = new KeywordTokenizer();
return new TokenStreamComponents(t,
new GermanStemFilter(new LowerCaseFilter(TEST_VERSION_CURRENT, t)));
}
};
public void testStemming() throws Exception {
InputStream vocOut = getClass().getResourceAsStream("data.txt");
assertVocabulary(analyzer, vocOut);
vocOut.close();
}
// LUCENE-3043: we use keywordtokenizer in this test,
// so ensure the stemmer does not crash on zero-length strings.
public void testEmpty() throws Exception {
assertAnalyzesTo(analyzer, "", new String[] { "" });
}
public void testKeyword() throws IOException {
final CharArraySet exclusionSet = new CharArraySet(TEST_VERSION_CURRENT, asSet("sängerinnen"), false);
Analyzer a = new Analyzer() {
@Override
protected TokenStreamComponents createComponents(String fieldName) {
Tokenizer source = new MockTokenizer(MockTokenizer.WHITESPACE, false);
TokenStream sink = new SetKeywordMarkerFilter(source, exclusionSet);
return new TokenStreamComponents(source, new GermanStemFilter(sink));
}
};
checkOneTerm(a, "sängerinnen", "sängerinnen");
}
/** blast some random strings through the analyzer */
public void testRandomStrings() throws Exception {
checkRandomData(random(), analyzer, 1000*RANDOM_MULTIPLIER);
}
public void testEmptyTerm() throws IOException {
Analyzer a = new Analyzer() {
@Override
protected TokenStreamComponents createComponents(String fieldName) {
Tokenizer tokenizer = new KeywordTokenizer();
return new TokenStreamComponents(tokenizer, new GermanStemFilter(tokenizer));
}
};
checkOneTerm(a, "", "");
}
}