/**
* License Agreement for OpenSearchServer
*
* Copyright (C) 2014 Emmanuel Keller / Jaeksoft
*
* http://www.open-search-server.com
*
* This file is part of OpenSearchServer.
*
* OpenSearchServer is free software: you can redistribute it and/or
* modify it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* OpenSearchServer is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with OpenSearchServer.
* If not, see <http://www.gnu.org/licenses/>.
**/
package com.jaeksoft.searchlib.analysis.filter;
import java.io.IOException;
import java.util.ArrayDeque;
import java.util.Deque;
import org.apache.lucene.analysis.TokenStream;
import com.jaeksoft.searchlib.SearchLibException;
import com.jaeksoft.searchlib.analysis.ClassPropertyEnum;
import com.jaeksoft.searchlib.analysis.FilterFactory;
import com.jaeksoft.searchlib.util.StringUtils;
public class AcronymFilter extends FilterFactory {
private boolean expand = false;
@Override
public void initProperties() throws SearchLibException {
super.initProperties();
addProperty(ClassPropertyEnum.EXPAND, Boolean.FALSE.toString(),
ClassPropertyEnum.BOOLEAN_LIST, 0, 0);
}
@Override
public void checkValue(ClassPropertyEnum prop, String value)
throws SearchLibException {
if (prop == ClassPropertyEnum.EXPAND)
expand = Boolean.parseBoolean(value);
}
@Override
public TokenStream create(TokenStream tokenStream) {
return new AcronymTokenFilter(tokenStream);
}
public class AcronymTokenFilter extends AbstractTermFilter {
private final Deque<String> termsQueue;
private int increment;
public AcronymTokenFilter(final TokenStream input) {
super(input);
termsQueue = new ArrayDeque<String>(0);
}
private final boolean popToken() {
if (termsQueue.isEmpty())
return false;
final String term = termsQueue.poll();
createToken(term, termsQueue.isEmpty() ? increment : 0,
offsetAtt.startOffset(), offsetAtt.endOffset(),
typeAtt.type(), flagsAtt.getFlags());
return true;
}
final private String[] checkAcronyms(final String currentTerm) {
String[] letters = StringUtils.split(currentTerm, '.');
for (String letter : letters)
if (letter.length() != 1)
return null;
return letters;
}
@Override
public final boolean incrementToken() throws IOException {
for (;;) {
if (popToken())
return true;
if (!input.incrementToken())
return false;
String term = termAtt.toString();
String[] letters = checkAcronyms(term);
if (letters == null)
return true;
increment = posIncrAtt.getPositionIncrement();
if (expand)
termsQueue.offer(term);
termsQueue.offer(StringUtils.join(letters));
}
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append("Create token: " + this);
return sb.toString();
}
}
}