public static void main(String[] args) {
    PipelineOptionsFactory.register(KafkaStreamingWordCountOptions.class);
    KafkaStreamingWordCountOptions options =
        PipelineOptionsFactory.fromArgs(args).as(KafkaStreamingWordCountOptions.class);
    options.setJobName("KafkaExample - WindowSize: " + options.getWindowSize() + " seconds");
    options.setStreaming(true);
    options.setCheckpointingInterval(1000L);
    options.setNumberOfExecutionRetries(5);
    options.setExecutionRetryDelay(3000L);
    options.setRunner(FlinkPipelineRunner.class);

    System.out.println(
        options.getKafkaTopic()
            + " "
            + options.getZookeeper()
            + " "
            + options.getBroker()
            + " "
            + options.getGroup());
    Pipeline pipeline = Pipeline.create(options);

    Properties p = new Properties();
    p.setProperty("zookeeper.connect", options.getZookeeper());
    p.setProperty("bootstrap.servers", options.getBroker());
    p.setProperty("group.id", options.getGroup());

    // this is the Flink consumer that reads the input to
    // the program from a kafka topic.
    FlinkKafkaConsumer08<String> kafkaConsumer =
        new FlinkKafkaConsumer08<>(options.getKafkaTopic(), new SimpleStringSchema(), p);

    PCollection<String> words =
        pipeline
            .apply(Read.from(new UnboundedFlinkSource<>(kafkaConsumer)).named("StreamingWordCount"))
            .apply(ParDo.of(new ExtractWordsFn()))
            .apply(
                Window.<String>into(
                        FixedWindows.of(Duration.standardSeconds(options.getWindowSize())))
                    .triggering(AfterWatermark.pastEndOfWindow())
                    .withAllowedLateness(Duration.ZERO)
                    .discardingFiredPanes());

    PCollection<KV<String, Long>> wordCounts = words.apply(Count.<String>perElement());

    wordCounts.apply(ParDo.of(new FormatAsStringFn())).apply(TextIO.Write.to("./outputKafka.txt"));

    pipeline.run();
  }
Exemple #2
0
  @Test
  public void testTopEmptyWithIncompatibleWindows() {
    Pipeline p = TestPipeline.create();
    Bound<String> windowingFn = Window.<String>into(FixedWindows.of(Duration.standardDays(10L)));
    PCollection<String> input =
        p.apply(Create.timestamped(Collections.<String>emptyList(), Collections.<Long>emptyList()))
            .apply(windowingFn);

    expectedEx.expect(IllegalStateException.class);
    expectedEx.expectMessage("Top");
    expectedEx.expectMessage("GlobalWindows");
    expectedEx.expectMessage("withoutDefaults");
    expectedEx.expectMessage("asSingletonView");

    input.apply(Top.of(1, new OrderByLength()));
  }