JFlexTokenizer.java revision 6d7c6f82e644c205bc679ee5b1fa2929ec949963
/*
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* See LICENSE.txt included in this distribution for the specific
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/*
* Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
*/
package org.opensolaris.opengrok.analysis;
import java.io.CharArrayReader;
import java.io.IOException;
import java.io.Reader;
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;
/**
* this class was created because of lucene 2.4.1 update which introduced char[] in Tokens instead of String
* lucene 3.0.0 uses AttributeSource instead of Tokens to make things even easier :-D
* lucene 3.5.0 CharTermAttribute will be used
*
* Generally this is a "template" for all new Tokenizers, so be carefull when changing it,
* it will impact almost ALL symbol tokenizers in OpenGrok ...
*
* Created on August 24, 2009
* @author Lubos Kosco
*/
public abstract class JFlexTokenizer extends Tokenizer {
// default jflex scanner methods and variables
abstract public boolean yylex() throws IOException;
abstract public void yyreset(Reader reader);
abstract public void yyclose() throws IOException;
/**
* Reinitialize the tokenizer with new contents.
*
* @param contents a char buffer with text to tokenize
* @param length the number of characters to use from the char buffer
*/
public final void reInit(char[] contents, int length) {
yyreset(new CharArrayReader(contents, 0, length));
}
@Override
public final void close() throws IOException {
yyclose();
}
protected CharTermAttribute termAtt= addAttribute(CharTermAttribute.class);
protected OffsetAttribute offsetAtt= addAttribute(OffsetAttribute.class);
protected PositionIncrementAttribute posIncrAtt= addAttribute(PositionIncrementAttribute.class);
/**
* This will reinitalize internal AttributeImpls, or it returns false if end of input Reader ...
* @return false if no more tokens, otherwise true
* @throws java.io.IOException
*/
@Override
public boolean incrementToken() throws java.io.IOException {
return this.yylex();
}
protected void setAttribs(String str, int start, int end) {
//FIXME increasing below by one(default) might be tricky, need more analysis
// after lucene upgrade to 3.5 below is most probably not even needed
this.posIncrAtt.setPositionIncrement(1);
this.termAtt.setEmpty();
this.termAtt.append(str);
this.offsetAtt.setOffset(start, end);
}
}