Source code for pyspark.streaming.mqtt

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from py4j.java_gateway import Py4JJavaError

from pyspark.storagelevel import StorageLevel
from pyspark.serializers import UTF8Deserializer
from pyspark.streaming import DStream

__all__ = ['MQTTUtils']

[docs]class MQTTUtils(object): @staticmethod
[docs] def createStream(ssc, brokerUrl, topic, storageLevel=StorageLevel.MEMORY_AND_DISK_SER_2): """ Create an input stream that pulls messages from a Mqtt Broker. :param ssc: StreamingContext object :param brokerUrl: Url of remote mqtt publisher :param topic: topic name to subscribe to :param storageLevel: RDD storage level. :return: A DStream object """ jlevel = ssc._sc._getJavaStorageLevel(storageLevel) try: helperClass = \ .loadClass("org.apache.spark.streaming.mqtt.MQTTUtilsPythonHelper") helper = helperClass.newInstance() jstream = helper.createStream(ssc._jssc, brokerUrl, topic, jlevel) except Py4JJavaError as e: if 'ClassNotFoundException' in str(e.java_exception): MQTTUtils._printErrorMsg(ssc.sparkContext) raise e return DStream(jstream, ssc, UTF8Deserializer())
@staticmethod def _printErrorMsg(sc): print(""" ________________________________________________________________________________________________ Spark Streaming's MQTT libraries not found in class path. Try one of the following. 1. Include the MQTT library and its dependencies with in the spark-submit command as $ bin/spark-submit --packages org.apache.spark:spark-streaming-mqtt:%s ... 2. Download the JAR of the artifact from Maven Central, Group Id = org.apache.spark, Artifact Id = spark-streaming-mqtt-assembly, Version = %s. Then, include the jar in the spark-submit command as $ bin/spark-submit --jars <spark-streaming-mqtt-assembly.jar> ... ________________________________________________________________________________________________ """ % (sc.version, sc.version))