Lucene example source code file (PrefixAndSuffixAwareTokenFilter.java)

This example Lucene source code file (PrefixAndSuffixAwareTokenFilter.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

io, ioexception, ioexception, override, override, prefixandsuffixawaretokenfilter, prefixawaretokenfilter, token, token, tokenstream, tokenstream

The Lucene PrefixAndSuffixAwareTokenFilter.java source code

package org.apache.lucene.analysis.miscellaneous;

/**
 * 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 org.apache.lucene.analysis.Token;
import org.apache.lucene.analysis.TokenStream;

import java.io.IOException;

/**
 * Links two {@link PrefixAwareTokenFilter}.
 * <p/>
 * <b>NOTE: This filter might not behave correctly if used with custom Attributes, i.e. Attributes other than
 * the ones located in org.apache.lucene.analysis.tokenattributes. 
 */
public class PrefixAndSuffixAwareTokenFilter extends TokenStream {

  private PrefixAwareTokenFilter suffix;

  public PrefixAndSuffixAwareTokenFilter(TokenStream prefix, TokenStream input, TokenStream suffix) {
    super(suffix);
    prefix = new PrefixAwareTokenFilter(prefix, input) {
      @Override
      public Token updateSuffixToken(Token suffixToken, Token lastInputToken) {
        return PrefixAndSuffixAwareTokenFilter.this.updateInputToken(suffixToken, lastInputToken);
      }
    };
    this.suffix = new PrefixAwareTokenFilter(prefix, suffix) {
      @Override
      public Token updateSuffixToken(Token suffixToken, Token lastInputToken) {
        return PrefixAndSuffixAwareTokenFilter.this.updateSuffixToken(suffixToken, lastInputToken);
      }
    };
  }

  public Token updateInputToken(Token inputToken, Token lastPrefixToken) {
    inputToken.setStartOffset(lastPrefixToken.endOffset() + inputToken.startOffset());
    inputToken.setEndOffset(lastPrefixToken.endOffset() + inputToken.endOffset());
    return inputToken;
  }

  public Token updateSuffixToken(Token suffixToken, Token lastInputToken) {
    suffixToken.setStartOffset(lastInputToken.endOffset() + suffixToken.startOffset());
    suffixToken.setEndOffset(lastInputToken.endOffset() + suffixToken.endOffset());
    return suffixToken;
  }


  @Override
  public final boolean incrementToken() throws IOException {
    return suffix.incrementToken();
  }

  @Override
  public void reset() throws IOException {
    suffix.reset();
  }


  @Override
  public void close() throws IOException {
    suffix.close();
  }

  @Override
  public void end() throws IOException {
    suffix.end();
  }
}