| 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 org.apache.lucene.analysis.tokenattributes.TermAttribute; |
| |
| /** |
| * Removes words that are too long or too short from the stream. |
| */ |
| public final class LengthFilter extends TokenFilter { |
| |
| final int min; |
| final int max; |
| |
| private TermAttribute termAtt; |
| |
| /** |
| * Build a filter that removes words that are too long or too |
| * short from the text. |
| */ |
| public LengthFilter(TokenStream in, int min, int max) |
| { |
| super(in); |
| this.min = min; |
| this.max = max; |
| termAtt = addAttribute(TermAttribute.class); |
| } |
| |
| /** |
| * Returns the next input Token whose term() is the right len |
| */ |
| @Override |
| public final boolean incrementToken() throws IOException { |
| // return the first non-stop word found |
| while (input.incrementToken()) { |
| int len = termAtt.termLength(); |
| if (len >= min && len <= max) { |
| return true; |
| } |
| // note: else we ignore it but should we index each part of it? |
| } |
| // reached EOS -- return false |
| return false; |
| } |
| } |