content: /**
   * 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.solr.analysis;
  
  import org.apache.commons.codec.Encoder;
  import org.apache.lucene.analysis.TokenFilter;
  import org.apache.lucene.analysis.TokenStream;
  import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
  import org.apache.lucene.analysis.tokenattributes.PositionIncrementAttribute;
  
  import java.io.IOException;
  
  /**
   * Create tokens for phonetic matches.  See:
   * http://jakarta.apache.org/commons/codec/api-release/org/apache/commons/codec/language/package-summary.html
   *
   * @version $Id: PhoneticFilter.java 940806 2010-05-04 11:18:46Z uschindler $
   */
  public final class PhoneticFilter extends TokenFilter 
  {
    protected boolean inject = true; 
    protected Encoder encoder = null;
    protected String name = null;
    
    protected State save = null;
    private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
    private final PositionIncrementAttribute posAtt = addAttribute(PositionIncrementAttribute.class);
  
    public PhoneticFilter(TokenStream in, Encoder encoder, String name, boolean inject) {
      super(in);
      this.encoder = encoder;
      this.name = name;
      this.inject = inject;   
    }
  
    @Override
    public boolean incrementToken() throws IOException {
      if( save != null ) {
        // clearAttributes();  // not currently necessary
        restoreState(save);
        save = null;
        return true;
      }
  
      if (!input.incrementToken()) return false;
  
      // pass through zero-length terms
      if (termAtt.length() == 0) return true;
  
      String value = termAtt.toString();
      String phonetic = null;
      try {
       String v = encoder.encode(value).toString();
       if (v.length() > 0 && !value.equals(v)) phonetic = v;
      } catch (Exception ignored) {} // just use the direct text
  
      if (phonetic == null) return true;
  
      if (!inject) {
        // just modify this token
        termAtt.setEmpty().append(phonetic);
        return true;
      }
  
      // We need to return both the original and the phonetic tokens.
      // to avoid a orig=captureState() change_to_phonetic() saved=captureState()  restoreState(orig)
      // we return the phonetic alternative first
  
      int origOffset = posAtt.getPositionIncrement();
      posAtt.setPositionIncrement(0);
      save = captureState();
  
      posAtt.setPositionIncrement(origOffset);
      termAtt.setEmpty().append(phonetic);
      return true;
    }
  
    @Override
    public void reset() throws IOException {
      input.reset();
      save = null;
    }
  }
  