address comments

Author: prabeesh

examples/src/main/python/streaming/mqtt_wordcount.py

@@ -25,7 +25,7 @@
   `$ bin/run-example \
        org.apache.spark.examples.streaming.MQTTPublisher tcp://localhost:1883 foo`
  and then run the example as
-    `$ bin/spark-submit --driver-class-path external/mqtt-assembly/target/scala-*/\
+    `$ bin/spark-submit --jars external/mqtt-assembly/target/scala-*/\
       spark-streaming-mqtt-assembly-*.jar examples/src/main/python/streaming/mqtt_wordcount.py \
       tcp://localhost:1883 foo`
 """

external/mqtt-assembly/pom.xml

@@ -21,14 +21,14 @@
   <parent>
     <groupId>org.apache.spark</groupId>
     <artifactId>spark-parent_2.10</artifactId>
-    <version>1.4.0-SNAPSHOT</version>
+    <version>1.5.0-SNAPSHOT</version>
     <relativePath>../../pom.xml</relativePath>
   </parent>
 
   <groupId>org.apache.spark</groupId>
   <artifactId>spark-streaming-mqtt-assembly_2.10</artifactId>
   <packaging>jar</packaging>
-  <name>Spark Project External Kafka Assembly</name>
+  <name>Spark Project External MQTT Assembly</name>
   <url>http://spark.apache.org/</url>
 
   <properties>

python/pyspark/streaming/mqtt.py

@@ -44,12 +44,28 @@ def createStream(ssc, brokerUrl, topic,
 
         try:
             jstream = ssc._jvm.MQTTUtils.createStream(ssc._jssc, brokerUrl, topic, jlevel)
-
         except Py4JError, e:
-            # TODO: use --jar once it also work on driver
-            if not e.message or 'call a package' in e.message:
-                print "No Mqtt package, please put the assembly jar into classpath:"
-                print " $ bin/spark-submit --driver-class-path external/mqtt-assembly/target/" + \
-                      "scala-*/spark-streaming-mqtt-assembly-*.jar"
+	    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 http://search.maven.org/,
+     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))