/*
 * 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.path;

import java.io.IOException;

import org.apache.lucene.analysis.Tokenizer;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
import org.apache.lucene.analysis.tokenattributes.OffsetAttribute;
import org.apache.lucene.analysis.tokenattributes.PositionIncrementAttribute;
import org.apache.lucene.util.AttributeFactory;

Tokenizer for path-like hierarchies.

Take something like:

 /something/something/else
and make:
 /something
 /something/something
 /something/something/else
/** * Tokenizer for path-like hierarchies. * <p> * Take something like: * * <pre> * /something/something/else * </pre> * * and make: * * <pre> * /something * /something/something * /something/something/else * </pre> */
public class PathHierarchyTokenizer extends Tokenizer { public PathHierarchyTokenizer() { this( DEFAULT_BUFFER_SIZE, DEFAULT_DELIMITER, DEFAULT_DELIMITER, DEFAULT_SKIP); } public PathHierarchyTokenizer( int skip) { this( DEFAULT_BUFFER_SIZE, DEFAULT_DELIMITER, DEFAULT_DELIMITER, skip); } public PathHierarchyTokenizer( int bufferSize, char delimiter) { this( bufferSize, delimiter, delimiter, DEFAULT_SKIP); } public PathHierarchyTokenizer(char delimiter, char replacement) { this(DEFAULT_BUFFER_SIZE, delimiter, replacement, DEFAULT_SKIP); } public PathHierarchyTokenizer(char delimiter, char replacement, int skip) { this(DEFAULT_BUFFER_SIZE, delimiter, replacement, skip); } public PathHierarchyTokenizer(AttributeFactory factory, char delimiter, char replacement, int skip) { this(factory, DEFAULT_BUFFER_SIZE, delimiter, replacement, skip); } public PathHierarchyTokenizer(int bufferSize, char delimiter, char replacement, int skip) { this(DEFAULT_TOKEN_ATTRIBUTE_FACTORY, bufferSize, delimiter, replacement, skip); } public PathHierarchyTokenizer (AttributeFactory factory, int bufferSize, char delimiter, char replacement, int skip) { super(factory); if (bufferSize < 0) { throw new IllegalArgumentException("bufferSize cannot be negative"); } if (skip < 0) { throw new IllegalArgumentException("skip cannot be negative"); } termAtt.resizeBuffer(bufferSize); this.delimiter = delimiter; this.replacement = replacement; this.skip = skip; resultToken = new StringBuilder(bufferSize); } private static final int DEFAULT_BUFFER_SIZE = 1024; public static final char DEFAULT_DELIMITER = '/'; public static final int DEFAULT_SKIP = 0; private final char delimiter; private final char replacement; private final int skip; private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class); private final OffsetAttribute offsetAtt = addAttribute(OffsetAttribute.class); private final PositionIncrementAttribute posAtt = addAttribute(PositionIncrementAttribute.class); private int startPosition = 0; private int skipped = 0; private boolean endDelimiter = false; private StringBuilder resultToken; private int charsRead = 0; @Override public final boolean incrementToken() throws IOException { clearAttributes(); termAtt.append( resultToken ); if(resultToken.length() == 0){ posAtt.setPositionIncrement(1); } else{ posAtt.setPositionIncrement(0); } int length = 0; boolean added = false; if( endDelimiter ){ termAtt.append(replacement); length++; endDelimiter = false; added = true; } while (true) { int c = input.read(); if (c >= 0) { charsRead++; } else { if( skipped > skip ) { length += resultToken.length(); termAtt.setLength(length); offsetAtt.setOffset(correctOffset(startPosition), correctOffset(startPosition + length)); if( added ){ resultToken.setLength(0); resultToken.append(termAtt.buffer(), 0, length); } return added; } else{ return false; } } if( !added ){ added = true; skipped++; if( skipped > skip ){ termAtt.append(c == delimiter ? replacement : (char)c); length++; } else { startPosition++; } } else { if( c == delimiter ){ if( skipped > skip ){ endDelimiter = true; break; } skipped++; if( skipped > skip ){ termAtt.append(replacement); length++; } else { startPosition++; } } else { if( skipped > skip ){ termAtt.append((char)c); length++; } else { startPosition++; } } } } length += resultToken.length(); termAtt.setLength(length); offsetAtt.setOffset(correctOffset(startPosition), correctOffset(startPosition+length)); resultToken.setLength(0); resultToken.append(termAtt.buffer(), 0, length); return true; } @Override public final void end() throws IOException { super.end(); // set final offset int finalOffset = correctOffset(charsRead); offsetAtt.setOffset(finalOffset, finalOffset); } @Override public void reset() throws IOException { super.reset(); resultToken.setLength(0); charsRead = 0; endDelimiter = false; skipped = 0; startPosition = 0; } }