/**
* 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.charfilter;
import java.io.IOException;
import org.apache.lucene.analysis.CharStream;
import org.apache.lucene.analysis.Tokenizer;
/**
* Subclasses of CharFilter can be chained to filter CharStream.
* They can be used as {@link java.io.Reader} with additional offset
* correction. {@link Tokenizer}s will automatically use {@link #correctOffset}
* if a CharFilter/CharStream subclass is used.
*/
public abstract class CharFilter extends CharStream {
protected CharStream input;
protected CharFilter(CharStream in) {
input = in;
}
/**
* Subclass may want to override to correct the current offset.
*
* @param currentOff current offset
* @return corrected offset
*/
protected int correct(int currentOff) {
return currentOff;
}
/**
* Chains the corrected offset through the input
* CharFilter.
*/
@Override
public final int correctOffset(int currentOff) {
return input.correctOffset(correct(currentOff));
}
@Override
public void close() throws IOException {
input.close();
}
@Override
public int read(char[] cbuf, int off, int len) throws IOException {
return input.read(cbuf, off, len);
}
@Override
public boolean markSupported(){
return input.markSupported();
}
@Override
public void mark( int readAheadLimit ) throws IOException {
input.mark(readAheadLimit);
}
@Override
public void reset() throws IOException {
input.reset();
}
}