Spark Streaming transformation 中部分代码不会执行

[Joy_s]

在ExceptionUser类reduceByKey这个算子中，调用了Print.print()方法，但这个方法为什么在spark streaming运行中不执行呢？

public class ExceptionUser {
	private static Logger logger = Logger.getLogger(ExceptionUser.class);
	private static final String KAFKA_TOPIC = "TopicA";
	public static void main(String[] args) throws Exception {
		System.setProperty("hadoop.home.dir", "D:\\checkpoint\\hadoop-common-2.2.0-bin-master");
		SparkConf conf = new SparkConf().setMaster("local
"
).setAppName("WordsCount");
		JavaStreamingContext jssc = new JavaStreamingContext(conf, Durations.milliseconds(4000));

		Map<String, String> kafkaParams = new HashMap<String, String>();
		kafkaParams.put("bootstrap.servers", "127.0.0.1:9092");
		kafkaParams.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
		kafkaParams.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
		kafkaParams.put("group.id", "lingroup");
		//kafkaParams.put("auto.offset.reset", "latest");
		
		Set<String> topics = new HashSet<String>();
        topics.add(KAFKA_TOPIC);
		
        JavaPairInputDStream<String, String> stream = org.apache.spark.streaming.kafka.KafkaUtils.
			createDirectStream(jssc, String.class, String.class, StringDecoder.class, StringDecoder.class, kafkaParams, topics);
        
        JavaPairDStream<String, Integer> transDStream = stream.flatMap(new FlatMapFunction<Tuple2<String,String>, String>() {
			public Iterator<String> call(Tuple2<String, String> t) throws Exception {
				return Arrays.asList(t._2.split(" ")).iterator();
			}
		}).mapToPair(new PairFunction<String, String, Integer>() {
			public Tuple2<String, Integer> call(String t) throws Exception {
				return new Tuple2<String, Integer>(t, 1);
			}
		}).reduceByKey(new Function2<Integer, Integer, Integer>() {
			public Integer call(Integer v1, Integer v2) throws Exception {
				// 这一行代码不执行
				Print.print(v1);
				// 这一行也不执行
				System.out.println("#######"  +  v1);
				return v1 + v2;
			}
		});
        
        transDStream.print();
        
		jssc.checkpoint("file:///D:/checkpoint/");
		jssc.start();
		jssc.awaitTermination();
	}
}

public class Print {

	public static void print(Integer i){
		
		System.out.println("--------------------------------");
		System.out.println(i);
		System.out.println("--------------------------------");
		
	}

}

[张某码]

你确定获取到了数据吗？在本地debug下看看咯