package org.apache.lucene.analysis.icu;
/*
* 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.
*/
import java.util.Map;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.icu.ICUTransformFilter;
import org.apache.lucene.analysis.util.AbstractAnalysisFactory; // javadocs
import org.apache.lucene.analysis.util.MultiTermAwareComponent;
import org.apache.lucene.analysis.util.TokenFilterFactory;
import com.ibm.icu.text.Transliterator;
/**
* Factory for {@link ICUTransformFilter}.
* <p>
* Supports the following attributes:
* <ul>
* <li>id (mandatory): A Transliterator ID, one from {@link Transliterator#getAvailableIDs()}
* <li>direction (optional): Either 'forward' or 'reverse'. Default is forward.
* </ul>
* @see Transliterator
*/
public class ICUTransformFilterFactory extends TokenFilterFactory implements MultiTermAwareComponent {
private Transliterator transliterator;
/** Sole constructor. See {@link AbstractAnalysisFactory} for initialization lifecycle. */
public ICUTransformFilterFactory() {}
// TODO: add support for custom rules
@Override
public void init(Map<String,String> args) {
super.init(args);
String id = args.get("id");
if (id == null) {
throw new IllegalArgumentException("id is required.");
}
int dir;
String direction = args.get("direction");
if (direction == null || direction.equalsIgnoreCase("forward"))
dir = Transliterator.FORWARD;
else if (direction.equalsIgnoreCase("reverse"))
dir = Transliterator.REVERSE;
else
throw new IllegalArgumentException("invalid direction: " + direction);
transliterator = Transliterator.getInstance(id, dir);
}
@Override
public TokenStream create(TokenStream input) {
return new ICUTransformFilter(input, transliterator);
}
@Override
public AbstractAnalysisFactory getMultiTermComponent() {
return this;
}
}