/**
* Copyright 2007 The Apache Software Foundation
*
* Licensed 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 com.sohospace.lucene.analysis.xanalyzer.collector;
import java.util.Iterator;
import java.util.LinkedList;
import org.apache.lucene.analysis.Token;
import com.sohospace.lucene.analysis.xanalyzer.TokenCollector;
/**
*
* @author Zhiliang Wang [qieqie.wang@gmail.com]
*
* @since 1.1
*/
public class QueryTokenCollector implements TokenCollector {
/**
* �洢��ǰ��knife�ֽ���ɵ�Token����
*
*/
private LinkedList<Token> tokens = new LinkedList<Token>();
private Token candidate;
private Token last;
public Iterator<Token> iterator() {
if (candidate != null) {
this.tokens.add(candidate);
candidate = null;
}
Iterator<Token> iter = this.tokens.iterator();
this.tokens = new LinkedList<Token>();
return iter;
}
public void collect(String word, int offset, int end) {
Token c = candidate != null ? candidate : last;
if (c == null) {
candidate = new Token(word, offset, end);
} else if (offset == c.startOffset()) {
if (end > c.endOffset()) {
candidate = new Token(word, offset, end);
}
} else if (offset > c.startOffset()) {
if (candidate != null) {
select(candidate);
}
if (end > c.endOffset()) {
candidate = new Token(word, offset, end);
} else {
candidate = null;
}
} else if (end >= c.endOffset()) {
if (last != null && last.startOffset() >= offset
&& last.endOffset() <= end) {
for (Iterator iter = tokens.iterator(); iter.hasNext();) {
last = (Token) iter.next();
if (last.startOffset() >= offset && last.endOffset() <= end) {
iter.remove();
}
}
}
last = null;
candidate = new Token(word, offset, end);
}
}
protected void select(Token t) {
this.tokens.add(t);
this.last = t;
}
}