X-Git-Url: https://git.mdrn.pl/pylucene.git/blobdiff_plain/a2e61f0c04805cfcb8706176758d1283c7e3a55c..aaeed5504b982cf3545252ab528713250aa33eed:/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/analysis/StopFilter.java diff --git a/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/analysis/StopFilter.java b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/analysis/StopFilter.java new file mode 100644 index 0000000..bc19ac2 --- /dev/null +++ b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/analysis/StopFilter.java @@ -0,0 +1,265 @@ +package org.apache.lucene.analysis; + +/** + * 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.Arrays; +import java.util.Set; +import java.util.List; + +import org.apache.lucene.analysis.tokenattributes.CharTermAttribute; +import org.apache.lucene.queryParser.QueryParser; // for javadoc +import org.apache.lucene.util.Version; + +/** + * Removes stop words from a token stream. + * + * + *

You must specify the required {@link Version} + * compatibility when creating StopFilter: + *

+ */ +public final class StopFilter extends FilteringTokenFilter { + + private final CharArraySet stopWords; + private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class); + + /** + * Construct a token stream filtering the given input. + * If stopWords is an instance of {@link CharArraySet} (true if + * makeStopSet() was used to construct the set) it will be directly used + * and ignoreCase will be ignored since CharArraySet + * directly controls case sensitivity. + *

+ * If stopWords is not an instance of {@link CharArraySet}, + * a new CharArraySet will be constructed and ignoreCase will be + * used to specify the case sensitivity of that set. + * + * @param enablePositionIncrements true if token positions should record the removed stop words + * @param input Input TokenStream + * @param stopWords A Set of Strings or char[] or any other toString()-able set representing the stopwords + * @param ignoreCase if true, all words are lower cased first + * @deprecated use {@link #StopFilter(Version, TokenStream, Set, boolean)} instead + */ + @Deprecated + public StopFilter(boolean enablePositionIncrements, TokenStream input, Set stopWords, boolean ignoreCase) + { + this(Version.LUCENE_30, enablePositionIncrements, input, stopWords, ignoreCase); + } + + /** + * Construct a token stream filtering the given input. If + * stopWords is an instance of {@link CharArraySet} (true if + * makeStopSet() was used to construct the set) it will be + * directly used and ignoreCase will be ignored since + * CharArraySet directly controls case sensitivity. + *

+ * If stopWords is not an instance of {@link CharArraySet}, a new + * CharArraySet will be constructed and ignoreCase will be used + * to specify the case sensitivity of that set. + * + * @param matchVersion + * Lucene version to enable correct Unicode 4.0 behavior in the stop + * set if Version > 3.0. See above for details. + * @param input + * Input TokenStream + * @param stopWords + * A Set of Strings or char[] or any other toString()-able set + * representing the stopwords + * @param ignoreCase + * if true, all words are lower cased first + */ + public StopFilter(Version matchVersion, TokenStream input, Set stopWords, boolean ignoreCase) + { + this(matchVersion, matchVersion.onOrAfter(Version.LUCENE_29), input, stopWords, ignoreCase); + } + + /* + * convenience ctor to enable deprecated ctors to set posInc explicitly + */ + private StopFilter(Version matchVersion, boolean enablePositionIncrements, TokenStream input, Set stopWords, boolean ignoreCase){ + super(enablePositionIncrements, input); + this.stopWords = stopWords instanceof CharArraySet ? (CharArraySet)stopWords : new CharArraySet(matchVersion, stopWords, ignoreCase); + } + + /** + * Constructs a filter which removes words from the input + * TokenStream that are named in the Set. + * + * @param enablePositionIncrements true if token positions should record the removed stop words + * @param in Input stream + * @param stopWords A Set of Strings or char[] or any other toString()-able set representing the stopwords + * @see #makeStopSet(Version, java.lang.String[]) + * @deprecated use {@link #StopFilter(Version, TokenStream, Set)} instead + */ + @Deprecated + public StopFilter(boolean enablePositionIncrements, TokenStream in, Set stopWords) { + this(Version.LUCENE_30, enablePositionIncrements, in, stopWords, false); + } + + /** + * Constructs a filter which removes words from the input TokenStream that are + * named in the Set. + * + * @param matchVersion + * Lucene version to enable correct Unicode 4.0 behavior in the stop + * set if Version > 3.0. See above for details. + * @param in + * Input stream + * @param stopWords + * A Set of Strings or char[] or any other toString()-able set + * representing the stopwords + * @see #makeStopSet(Version, java.lang.String[]) + */ + public StopFilter(Version matchVersion, TokenStream in, Set stopWords) { + this(matchVersion, in, stopWords, false); + } + + /** + * Builds a Set from an array of stop words, + * appropriate for passing into the StopFilter constructor. + * This permits this stopWords construction to be cached once when + * an Analyzer is constructed. + * + * @see #makeStopSet(Version, java.lang.String[], boolean) passing false to ignoreCase + * @deprecated use {@link #makeStopSet(Version, String...)} instead + */ + @Deprecated + public static final Set makeStopSet(String... stopWords) { + return makeStopSet(Version.LUCENE_30, stopWords, false); + } + + /** + * Builds a Set from an array of stop words, + * appropriate for passing into the StopFilter constructor. + * This permits this stopWords construction to be cached once when + * an Analyzer is constructed. + * + * @param matchVersion Lucene version to enable correct Unicode 4.0 behavior in the returned set if Version > 3.0 + * @param stopWords An array of stopwords + * @see #makeStopSet(Version, java.lang.String[], boolean) passing false to ignoreCase + */ + public static final Set makeStopSet(Version matchVersion, String... stopWords) { + return makeStopSet(matchVersion, stopWords, false); + } + + /** + * Builds a Set from an array of stop words, + * appropriate for passing into the StopFilter constructor. + * This permits this stopWords construction to be cached once when + * an Analyzer is constructed. + * @param stopWords A List of Strings or char[] or any other toString()-able list representing the stopwords + * @return A Set ({@link CharArraySet}) containing the words + * @see #makeStopSet(Version, java.lang.String[], boolean) passing false to ignoreCase + * @deprecated use {@link #makeStopSet(Version, List)} instead + */ + @Deprecated + public static final Set makeStopSet(List stopWords) { + return makeStopSet(Version.LUCENE_30, stopWords, false); + } + + /** + * Builds a Set from an array of stop words, + * appropriate for passing into the StopFilter constructor. + * This permits this stopWords construction to be cached once when + * an Analyzer is constructed. + * + * @param matchVersion Lucene version to enable correct Unicode 4.0 behavior in the returned set if Version > 3.0 + * @param stopWords A List of Strings or char[] or any other toString()-able list representing the stopwords + * @return A Set ({@link CharArraySet}) containing the words + * @see #makeStopSet(Version, java.lang.String[], boolean) passing false to ignoreCase + */ + public static final Set makeStopSet(Version matchVersion, List stopWords) { + return makeStopSet(matchVersion, stopWords, false); + } + + /** + * Creates a stopword set from the given stopword array. + * @param stopWords An array of stopwords + * @param ignoreCase If true, all words are lower cased first. + * @return a Set containing the words + * @deprecated use {@link #makeStopSet(Version, String[], boolean)} instead; + */ + @Deprecated + public static final Set makeStopSet(String[] stopWords, boolean ignoreCase) { + return makeStopSet(Version.LUCENE_30, stopWords, ignoreCase); + } + /** + * Creates a stopword set from the given stopword array. + * + * @param matchVersion Lucene version to enable correct Unicode 4.0 behavior in the returned set if Version > 3.0 + * @param stopWords An array of stopwords + * @param ignoreCase If true, all words are lower cased first. + * @return a Set containing the words + */ + public static final Set makeStopSet(Version matchVersion, String[] stopWords, boolean ignoreCase) { + CharArraySet stopSet = new CharArraySet(matchVersion, stopWords.length, ignoreCase); + stopSet.addAll(Arrays.asList(stopWords)); + return stopSet; + } + + /** + * Creates a stopword set from the given stopword list. + * @param stopWords A List of Strings or char[] or any other toString()-able list representing the stopwords + * @param ignoreCase if true, all words are lower cased first + * @return A Set ({@link CharArraySet}) containing the words + * @deprecated use {@link #makeStopSet(Version, List, boolean)} instead + */ + @Deprecated + public static final Set makeStopSet(List stopWords, boolean ignoreCase){ + return makeStopSet(Version.LUCENE_30, stopWords, ignoreCase); + } + + /** + * Creates a stopword set from the given stopword list. + * @param matchVersion Lucene version to enable correct Unicode 4.0 behavior in the returned set if Version > 3.0 + * @param stopWords A List of Strings or char[] or any other toString()-able list representing the stopwords + * @param ignoreCase if true, all words are lower cased first + * @return A Set ({@link CharArraySet}) containing the words + */ + public static final Set makeStopSet(Version matchVersion, List stopWords, boolean ignoreCase){ + CharArraySet stopSet = new CharArraySet(matchVersion, stopWords.size(), ignoreCase); + stopSet.addAll(stopWords); + return stopSet; + } + + /** + * Returns the next input Token whose term() is not a stop word. + */ + @Override + protected boolean accept() throws IOException { + return !stopWords.contains(termAtt.buffer(), 0, termAtt.length()); + } + + /** + * Returns version-dependent default for + * enablePositionIncrements. Analyzers that embed + * StopFilter use this method when creating the + * StopFilter. Prior to 2.9, this returns false. On 2.9 + * or later, it returns true. + * @deprecated use {@link #StopFilter(Version, TokenStream, Set)} instead + */ + @Deprecated + public static boolean getEnablePositionIncrementsVersionDefault(Version matchVersion) { + return matchVersion.onOrAfter(Version.LUCENE_29); + } +}