alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Lucene example source code file (DelimitedPayloadTokenFilter.java)

This example Lucene source code file (DelimitedPayloadTokenFilter.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

chartermattribute, default_delimiter, delimitedpayloadtokenfilter, delimitedpayloadtokenfilter, io, ioexception, ioexception, override, payloadattribute, payloadencoder, payloadencoder, tokenfilter, tokenfilter

The Lucene DelimitedPayloadTokenFilter.java source code

package org.apache.lucene.analysis.payloads;
/**
 * 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.io.IOException;

import org.apache.lucene.analysis.TokenFilter;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.tokenattributes.PayloadAttribute;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;


/**
 * Characters before the delimiter are the "token", those after are the payload.
 * <p/>
 * For example, if the delimiter is '|', then for the string "foo|bar", foo is the token
 * and "bar" is a payload.
 * <p/>
 * Note, you can also include a {@link org.apache.lucene.analysis.payloads.PayloadEncoder} to convert the payload in an appropriate way (from characters to bytes).
 * <p/>
 * Note make sure your Tokenizer doesn't split on the delimiter, or this won't work
 *
 * @see PayloadEncoder
 */
public final class DelimitedPayloadTokenFilter extends TokenFilter {
  public static final char DEFAULT_DELIMITER = '|';
  private final char delimiter;
  private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
  private final PayloadAttribute payAtt = addAttribute(PayloadAttribute.class);
  private final PayloadEncoder encoder;


  public DelimitedPayloadTokenFilter(TokenStream input, char delimiter, PayloadEncoder encoder) {
    super(input);
    this.delimiter = delimiter;
    this.encoder = encoder;
  }

  @Override
  public boolean incrementToken() throws IOException {
    if (input.incrementToken()) {
      final char[] buffer = termAtt.buffer();
      final int length = termAtt.length();
      for (int i = 0; i < length; i++) {
        if (buffer[i] == delimiter) {
          payAtt.setPayload(encoder.encode(buffer, i + 1, (length - (i + 1))));
          termAtt.setLength(i); // simply set a new length
          return true;
        }
      }
      // we have not seen the delimiter
      payAtt.setPayload(null);
      return true;
    } else return false;
  }
}

Other Lucene examples (source code examples)

Here is a short list of links related to this Lucene DelimitedPayloadTokenFilter.java source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.