Lucene example source code file (CharFilter.java)

This example Lucene source code file (CharFilter.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Lucene tags/keywords

charfilter, charfilter, charstream, charstream, io, ioexception, ioexception, override, override

The Lucene CharFilter.java source code

/**
 * 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;

import java.io.IOException;

/**
 * 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();
  }
}