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.malhar.stream.sample;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  
  import org.apache.commons.io.IOUtils;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.fs.FileSystem;
  import org.apache.hadoop.fs.Path;
  
  import com.google.common.base.Throwables;
  
  import com.datatorrent.api.Context;
  import com.datatorrent.api.DefaultOutputPort;
  import com.datatorrent.api.InputOperator;
  import com.datatorrent.common.util.BaseOperator;
  
  public class WCInput extends BaseOperator implements InputOperator
  {
    public final transient DefaultOutputPort<String> output = new DefaultOutputPort<>();
  
    private transient BufferedReader reader;
  
    @Override
    public void setup(Context.OperatorContext context)
    {
      initReader();
    }
  
    private void initReader()
    {
      try {
        Path myPath = new Path("/user/siyuan/wc/wordcount");
        FileSystem fs = FileSystem.get(new Configuration());
        reader = new BufferedReader(new InputStreamReader(fs.open(myPath)));
      } catch (Exception ex) {
        throw Throwables.propagate(ex);
      }
    }
  
    @Override
    public void teardown()
    {
      IOUtils.closeQuietly(reader);
    }
  
    @Override
    public void emitTuples()
    {
      try {
        String line = reader.readLine();
        if (line == null) {
          reader.close();
          initReader();
        } else {
          // simulate late data
          //long timestamp = System.currentTimeMillis() - (long)(Math.random() * 30000);
  
          this.output.emit(line);
        }
      } catch (IOException ex) {
        throw new RuntimeException(ex);
      }
    }
  
    @Override
    public void endWindow()
    {
      //this.controlOutput.emit(new WatermarkImpl(System.currentTimeMillis() - 15000));
    }
  }
  