/** Entry point for a streaming Fizz Buzz! */
public static void main(String[] args) throws Exception {
Topology topology = new Topology();
// Declare an infinite stream of Long values
TStream<Long> counting = BeaconStreams.longBeacon(topology);
// Throttle the rate to allow the output to be seen easier
counting = counting.throttle(100, TimeUnit.MILLISECONDS);
// Print the tuples to standard output
playFizzBuzz(counting).print();
// At this point the streaming topology (streaming) is
// declared, but no data is flowing. The topology
// must be submitted to a StreamsContext to be executed.
// Since this is an streaming graph with an endless
// data source it will run for ever
Future<?> runningTopology = StreamsContextFactory.getEmbedded().submit(topology);
// Run for one minute before canceling.
Thread.sleep(TimeUnit.MINUTES.toMillis(1));
runningTopology.cancel(true);
}
/**
* Publish some messages to a topic; subscribe to the topic and report received messages.
*
* @param contextType string value of a {@code StreamsContext.Type}
* @throws Exception
*/
public void publishSubscribe(String contextType) throws Exception {
Map<String, Object> contextConfig = new HashMap<>();
initContextConfig(contextConfig);
Topology top = new Topology("mqttSample");
// A compile time MQTT topic value.
Supplier<String> topic = new Value<String>(TOPIC);
// Create the MQTT connector
MqttStreams mqtt = new MqttStreams(top, createMqttConfig());
// Create a stream of messages and for the sample, give the
// consumer a change to become ready
TStream<Message> msgs = makeStreamToPublish(top).modify(initialDelayFunc(PUB_DELAY_MSEC));
// Publish the message stream to the topic
mqtt.publish(msgs, topic);
// Subscribe to the topic and report received messages
TStream<Message> rcvdMsgs = mqtt.subscribe(topic);
rcvdMsgs.print();
// Submit the topology, to send and receive the messages.
Future<?> future =
StreamsContextFactory.getStreamsContext(contextType).submit(top, contextConfig);
if (contextType.contains("DISTRIBUTED")) {
System.out.println(
"\nSee the job's PE console logs for the topology output.\n"
+ "Use Streams Studio or streamtool. e.g.,\n"
+ " # identify the job's \"Print\" PE\n"
+ " streamtool lspes --jobs "
+ future.get()
+ "\n"
+ " # print the PE's console log\n"
+ " streamtool viewlog --print --console --pe <the-peid>"
+ "\n");
System.out.println(
"Cancel the job using Streams Studio or streamtool. e.g.,\n"
+ " streamtool canceljob "
+ future.get()
+ "\n");
} else if (contextType.contains("STANDALONE")) {
Thread.sleep(15000);
future.cancel(true);
}
}
