RandomNumberGenerator.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
* <p>
* http://www.apache.org/licenses/LICENSE-2.0
* <p>
* 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.example.myapexapp;

import com.datatorrent.api.DefaultOutputPort;
import com.datatorrent.api.InputOperator;
import com.datatorrent.common.util.BaseOperator;

/**
 * This is a simple operator that emits random number.
 */
public class RandomNumberGenerator extends BaseOperator implements InputOperator
{
  private int numTuples = 100;
  private transient int count = 0;

  public final transient DefaultOutputPort<Double> out = new DefaultOutputPort<Double>();

  @Override
  public void beginWindow(long windowId)
  {
    count = 0;
  }

  @Override
  public void emitTuples()
  {
    if (count++ < numTuples) {
      out.emit(Math.random());
    }
  }

  public int getNumTuples()
  {
    return numTuples;
  }

  /**
   * Sets the number of tuples to be emitted every window.
   * @param numTuples number of tuples
   */
  public void setNumTuples(int numTuples)
  {
    this.numTuples = numTuples;
  }
}