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.apex.examples.wordcount;
  
  import org.apache.apex.malhar.lib.algo.UniqueCounter;
  import org.apache.apex.malhar.lib.io.ConsoleOutputOperator;
  import org.apache.hadoop.conf.Configuration;
  
  import com.datatorrent.api.DAG;
  import com.datatorrent.api.StreamingApplication;
  import com.datatorrent.api.annotation.ApplicationAnnotation;
  
  /**
   * Simple Word Count Example : <br>
   * This is application to count total occurrence of each word from file or any
   * stream. <br>
   * <br>
   *
   * Functional Description : <br>
   * This example declares custom input operator to read data file set by user. <br>
   * This input operator can be replaced by any stream input operator. <br>
   * <br>
   *
   * Custom Attribute(s) : None <br>
   * <br>
   *
   * Input Adapter : <br>
   * Word input operator opens user specified data file and streams each line to
   * application. <br>
   * <br>
   *
   * Output Adapter : <br>
   * Output values are written to console through ConsoleOutputOerator<br>
   * If needed you can use other output adapters<br>
   * <br>
   * <p>
   * Running Java Test or Main app in IDE:
   *
   * <pre>
   *     LocalMode.runApp(new Application(), 600000); // 10 min run
   * </pre>
   *
   * Run Success : <br>
   * For successful deployment and run, user should see following output on console: <br>
   * </pre>
   * {developed=1} {bush’s=2} {roster=1} {council=1} {mankiw=1} {academia=1}
   * {of=6} {help=1} {are=1} {presidential=1}
   * </pre> <br> <br>
   *
   * Scaling Options : <br>
   * This operator app can not be scaled, please look at implementation {@link org.apache.apex.malhar.lib.algo.UniqueCounterEach}  <br> <br>
   *
   * Application DAG : <br>
   * <img src="doc-files/UniqueWordCounter.jpg" width=600px > <br>
   *
   * Streaming Window Size : 500ms
   * Operator Details : <br>
   * <ul>
   * <li>
   * <p><b> The operator wordinput : </b> This operator opens local file, reads each line and sends each word to application.
   *         This can replaced by any input stream by user. <br>
   *     Class : {@link WordCountInputOperator}  <br>
   *     Operator Application Window Count : 1 <br>
   *     StateFull : No
   *  </li>
   *  <li>
   *     <p><b> The operator count : </b>  This operator aggregates unique key count  over one window count(app). <br>
   *     Class : {@link org.apache.apex.malhar.lib.algo.UniqueCounterEach}  <br>
   *     Operator Application Window Count : 1 <br>
   *     StateFull : No
   *  </li>
   *  <li>
   *      <p><b>The operator Console: </b> This operator just outputs the input tuples to  the console (or stdout).
   *      This case it emits unique count of each word over 500ms.
   *  </li>
   * </ul>
   *
   * @since 0.3.2
   */
  @ApplicationAnnotation(name = "WordCountExample")
  public class Application implements StreamingApplication
  {
    @Override
    public void populateDAG(DAG dag, Configuration conf)
    {
      WordCountInputOperator input = dag.addOperator("wordinput", new WordCountInputOperator());
      UniqueCounter<String> wordCount = dag.addOperator("count", new UniqueCounter<String>());
      dag.addStream("wordinput-count", input.outputPort, wordCount.data);
      ConsoleOutputOperator consoleOperator = dag.addOperator("console", new ConsoleOutputOperator());
      dag.addStream("count-console",wordCount.count, consoleOperator.input);
    }
  }
  