Java tutorial
/* * 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. */ package org.apache.lucene.analysis.tokenattributes; import org.apache.lucene.util.Attribute; /** Determines the position of this token * relative to the previous Token in a TokenStream, used in phrase * searching. * * <p>The default value is one. * * <p>Some common uses for this are:<ul> * * <li>Set it to zero to put multiple terms in the same position. This is * useful if, e.g., a word has multiple stems. Searches for phrases * including either stem will match. In this case, all but the first stem's * increment should be set to zero: the increment of the first instance * should be one. Repeating a token with an increment of zero can also be * used to boost the scores of matches on that token. * * <li>Set it to values greater than one to inhibit exact phrase matches. * If, for example, one does not want phrases to match across removed stop * words, then one could build a stop word filter that removes stop words and * also sets the increment to the number of stop words removed before each * non-stop word. Then exact phrase queries will only match when the terms * occur with no intervening stop words. * * </ul> * * @see org.apache.lucene.index.PostingsEnum */ public interface PositionIncrementAttribute extends Attribute { /** Set the position increment. The default value is one. * * @param positionIncrement the distance from the prior term * @throws IllegalArgumentException if <code>positionIncrement</code> * is negative. * @see #getPositionIncrement() */ public void setPositionIncrement(int positionIncrement); /** Returns the position increment of this Token. * @see #setPositionIncrement(int) */ public int getPositionIncrement(); }