org.apache.spark.streaming.mqtt

Class MQTTReceiver

Object

org.apache.spark.streaming.receiver.Receiver<String>

org.apache.spark.streaming.mqtt.MQTTReceiver

All Implemented Interfaces:

java.io.Serializable

public class MQTTReceiver
extends Receiver<String>

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
MQTTReceiver(String brokerUrl, String topic, StorageLevel storageLevel)

Method Summary

Methods

Modifier and Type	Method and Description
void	onStart() This method is called by the system when the receiver is started.
void	onStop() This method is called by the system when the receiver is stopped.

Methods inherited from class org.apache.spark.streaming.receiver.Receiver

attachExecutor, executor_, isStarted, isStopped, preferredLocation, reportError, restart, restart, restart, setReceiverId, stop, stop, storageLevel, store, store, store, store, store, store, store, store, store, streamId

Methods inherited from class Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MQTTReceiver

public MQTTReceiver(String brokerUrl,
            String topic,
            StorageLevel storageLevel)

Method Detail

onStop

public void onStop()

Description copied from class: Receiver

This method is called by the system when the receiver is stopped. All resources (threads, buffers, etc.) setup in onStart() must be cleaned up in this method.

Specified by:

onStop in class Receiver<String>

onStart

public void onStart()

Description copied from class: Receiver

This method is called by the system when the receiver is started. This function must initialize all resources (threads, buffers, etc.) necessary for receiving data. This function must be non-blocking, so receiving the data must occur on a different thread. Received data can be stored with Spark by calling store(data).

If there are errors in threads started here, then following options can be done (i) reportError(...) can be called to report the error to the driver. The receiving of data will continue uninterrupted. (ii) stop(...) can be called to stop receiving data. This will call onStop() to clear up all resources allocated (threads, buffers, etc.) during onStart(). (iii) restart(...) can be called to restart the receiver. This will call onStop() immediately, and then onStart() after a delay.

Specified by:

onStart in class Receiver<String>