--- /dev/null
+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.
+ *
+ * <a name="version"/>
+ * <p>You must specify the required {@link Version}
+ * compatibility when creating StopFilter:
+ * <ul>
+ * <li> As of 3.1, StopFilter correctly handles Unicode 4.0
+ * supplementary characters in stopwords and position
+ * increments are preserved
+ * </ul>
+ */
+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 <code>stopWords</code> is an instance of {@link CharArraySet} (true if
+ * <code>makeStopSet()</code> was used to construct the set) it will be directly used
+ * and <code>ignoreCase</code> will be ignored since <code>CharArraySet</code>
+ * directly controls case sensitivity.
+ * <p/>
+ * If <code>stopWords</code> is not an instance of {@link CharArraySet},
+ * a new CharArraySet will be constructed and <code>ignoreCase</code> 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
+ * <code>stopWords</code> is an instance of {@link CharArraySet} (true if
+ * <code>makeStopSet()</code> was used to construct the set) it will be
+ * directly used and <code>ignoreCase</code> will be ignored since
+ * <code>CharArraySet</code> directly controls case sensitivity.
+ * <p/>
+ * If <code>stopWords</code> is not an instance of {@link CharArraySet}, a new
+ * CharArraySet will be constructed and <code>ignoreCase</code> 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 <a href="#version">above</a> 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 <a href="#version">above</a> 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<Object> 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<Object> 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<Object> 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<Object> 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<Object> 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<Object> 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<Object> 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<Object> 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);
+ }
+}
fnp / pylucene.git / blobdiff