Worker.java

package pl.llp.aircasting.sensor;

import pl.llp.aircasting.util.Constants;

import com.google.common.eventbus.EventBus;

public abstract class Worker
{
  private static final long MAX_CONNECTION_FAILURE_TIME = Constants.ONE_MINUTE;

  protected final EventBus eventBus;

  private volatile long connectionFailingSince = -1;
  Status status = Status.NOT_YET_STARTED;

  Worker(EventBus eventBus)
  {
    this.eventBus = eventBus;
  }

  protected void considerStoppingOnFailure()
  {
    long currentTime = System.currentTimeMillis();
    if(connectionFailingSince < 0)
    {
      connectionFailingSince = currentTime;
    }
    else
    {
      long difference = currentTime - connectionFailingSince;
      if(difference > MAX_CONNECTION_FAILURE_TIME)
      {
        handlePersistentFailure();
        stop();
      }
    }
  }

  public void start()
  {
    status = Status.STARTED;
    customStart();
  }

  public void stop()
  {
    status = Status.STOPPED;
    customStop();
  }

  public abstract void customStart();

  public abstract void customStop();

  public abstract void handlePersistentFailure();
}