RegexHashtagExtractor.java

/*
 * 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.streams.regex;

import org.apache.streams.core.StreamsProcessor;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Processes the content of an {@link org.apache.streams.pojo.json.Activity} object to extract the Hashtags and add
 * them to the appropriate extensions object
 */
public class RegexHashtagExtractor extends AbstractRegexExtensionExtractor<String> implements StreamsProcessor {

  private static final String STREAMS_ID = "RegexHashtagExtractor";

  private static final Logger LOGGER = LoggerFactory.getLogger(RegexHashtagExtractor.class);

  public static final String DEFAULT_PATTERN = "#\\w+";
  public static final String PATTERN_CONFIG_KEY = "HashtagPattern";
  public static final String EXTENSION_KEY = "hashtags";

  public RegexHashtagExtractor() {
    super(PATTERN_CONFIG_KEY, EXTENSION_KEY, DEFAULT_PATTERN);
  }

  @Override
  public String getId() {
    return STREAMS_ID;
  }

  @Override
  protected String prepareObject(String extracted) {
    return extracted.substring(1);
  }
}