X-Git-Url: https://git.mdrn.pl/pylucene.git/blobdiff_plain/a2e61f0c04805cfcb8706176758d1283c7e3a55c..aaeed5504b982cf3545252ab528713250aa33eed:/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/miscellaneous/StemmerOverrideFilter.java?ds=sidebyside diff --git a/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/miscellaneous/StemmerOverrideFilter.java b/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/miscellaneous/StemmerOverrideFilter.java new file mode 100644 index 0000000..fa2a0c4 --- /dev/null +++ b/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/miscellaneous/StemmerOverrideFilter.java @@ -0,0 +1,70 @@ +package org.apache.lucene.analysis.miscellaneous; + +/** + * 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.util.Map; + +import org.apache.lucene.analysis.CharArrayMap; +import org.apache.lucene.analysis.TokenFilter; +import org.apache.lucene.analysis.TokenStream; +import org.apache.lucene.analysis.tokenattributes.KeywordAttribute; +import org.apache.lucene.analysis.tokenattributes.CharTermAttribute; +import org.apache.lucene.util.Version; + +/** + * Provides the ability to override any {@link KeywordAttribute} aware stemmer + * with custom dictionary-based stemming. + */ +public final class StemmerOverrideFilter extends TokenFilter { + private final CharArrayMap dictionary; + + private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class); + private final KeywordAttribute keywordAtt = addAttribute(KeywordAttribute.class); + + /** + * Create a new StemmerOverrideFilter, performing dictionary-based stemming + * with the provided dictionary. + *

+ * Any dictionary-stemmed terms will be marked with {@link KeywordAttribute} + * so that they will not be stemmed with stemmers down the chain. + *

+ */ + public StemmerOverrideFilter(Version matchVersion, TokenStream input, + Map dictionary) { + super(input); + this.dictionary = dictionary instanceof CharArrayMap ? + (CharArrayMap) dictionary : CharArrayMap.copy(matchVersion, dictionary); + } + + @Override + public boolean incrementToken() throws IOException { + if (input.incrementToken()) { + if (!keywordAtt.isKeyword()) { // don't muck with already-keyworded terms + String stem = dictionary.get(termAtt.buffer(), 0, termAtt.length()); + if (stem != null) { + termAtt.setEmpty().append(stem); + keywordAtt.setKeyword(true); + } + } + return true; + } else { + return false; + } + } +}