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+#
+# 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
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# 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.
+#
+
+"""
+ Consumes messages from one or more topics in Kafka and does wordcount.
+ Usage: structured_kafka_wordcount.py <bootstrap-servers> <subscribe-type> <topics>
+ <bootstrap-servers> The Kafka "bootstrap.servers" configuration. A
+ comma-separated list of host:port.
+ <subscribe-type> There are three kinds of type, i.e. 'assign', 'subscribe',
+ 'subscribePattern'.
+ |- <assign> Specific TopicPartitions to consume. Json string
+ | {"topicA":[0,1],"topicB":[2,4]}.
+ |- <subscribe> The topic list to subscribe. A comma-separated list of
+ | topics.
+ |- <subscribePattern> The pattern used to subscribe to topic(s).
+ | Java regex string.
+ |- Only one of "assign, "subscribe" or "subscribePattern" options can be
+ | specified for Kafka source.
+ <topics> Different value format depends on the value of 'subscribe-type'.
+
+ Run the example
+ `$ bin/spark-submit examples/src/main/python/sql/streaming/structured_kafka_wordcount.py \
+ host1:port1,host2:port2 subscribe topic1,topic2`
+"""
+from __future__ import print_function
+
+import sys
+
+from pyspark.sql import SparkSession
+from pyspark.sql.functions import explode
+from pyspark.sql.functions import split
+
+if __name__ == "__main__":
+ if len(sys.argv) != 4:
+ print("""
+ Usage: structured_kafka_wordcount.py <bootstrap-servers> <subscribe-type> <topics>
+ """, file=sys.stderr)
+ exit(-1)
+
+ bootstrapServers = sys.argv[1]
+ subscribeType = sys.argv[2]
+ topics = sys.argv[3]
+
+ spark = SparkSession\
+ .builder\
+ .appName("StructuredKafkaWordCount")\
+ .getOrCreate()
+
+ # Create DataSet representing the stream of input lines from kafka
+ lines = spark\
+ .readStream\
+ .format("kafka")\
+ .option("kafka.bootstrap.servers", bootstrapServers)\
+ .option(subscribeType, topics)\
+ .load()\
+ .selectExpr("CAST(value AS STRING)")
+
+ # Split the lines into words
+ words = lines.select(
+ # explode turns each item in an array into a separate row
+ explode(
+ split(lines.value, ' ')
+ ).alias('word')
+ )
+
+ # Generate running word count
+ wordCounts = words.groupBy('word').count()
+
+ # Start running the query that prints the running counts to the console
+ query = wordCounts\
+ .writeStream\
+ .outputMode('complete')\
+ .format('console')\
+ .start()
+
+ query.awaitTermination()