library/src/main/java/com/datatorrent/lib/logs/LineTokenizer.java

/*
 * Copyright (c) 2013 DataTorrent, Inc. ALL Rights Reserved.
 *
 * Licensed 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 com.datatorrent.lib.logs;

import com.datatorrent.api.DefaultOutputPort;
import com.datatorrent.api.annotation.*;
import com.datatorrent.lib.util.BaseLineTokenizer;

/**
 * This operator splits lines into tokens and emits token strings on the output port.
 * <p>
 * This module is a pass through. Ideal for applications like word count, or log
 * processing<br>
 * <br>
 * <b>StateFull : No, </b> tokens are processed in current window. <br>
 * <b>Partitions : Yes, </b> No state dependency in output tokens. <br>
 * <br>
 * <b>Ports</b>:<br>
 * <b>data</b>: expects String<br>
 * <b>tokens</b>: emits String<br>
 * <br>
 * <b>Properties</b>:<br>
 * <b>splitby</b>: The characters used to split the line. Default is ";\t "<br>
 * <br>
 * <br>
 * </p>
 * @displayName Line Tokenizer
 * @category Logs
 * @tags string
 *
 * @since 0.3.3
 */
@Stateless
@OperatorAnnotation(partitionable=true)
public class LineTokenizer extends BaseLineTokenizer
{
  /**
   * The is the output port that emits string tokens.
   */
	public final transient DefaultOutputPort<String> tokens = new DefaultOutputPort<String>();

	/**
	 * emits tokens on port "tokens" if tok is not empty
	 *
	 * @param tok
	 */
	@Override
	public void processToken(String tok)
	{
		if (!tok.isEmpty()) {
			tokens.emit(tok);
		}
	}
}