我正在尝试使用Spark流访问Kafka主题。我不认为我错过了任何依赖性或进口，但是当我尝试运行代码时，如下所示：
public static void main(String[] args) {
String URL = "spark://localhost:7077";
SparkConf conf = new SparkConf().setAppName("Kafka-test").setMaster(URL);
JavaStreamingContext ssc = new JavaStreamingContext(conf, Durations.seconds(1));
Map<String, Object> kafkaParams = new HashMap<>();
kafkaParams.put("bootstrap.servers", "localhost:6667");
kafkaParams.put("key.deserializer", StringDeserializer.class);
kafkaParams.put("value.deserializer", StringDeserializer.class);
kafkaParams.put("group.id", "ID1");
kafkaParams.put("auto.offset.reset", "latest");
kafkaParams.put("enable.auto.commit", false);
Collection<String> topics = Arrays.asList("MAX_LEGO", "CanBeDeleted");
JavaInputDStream<ConsumerRecord<String, String>> stream = KafkaUtils.createDirectStream(ssc,
LocationStrategies.PreferConsistent(),
ConsumerStrategies.<String, String>Subscribe(topics, kafkaParams));
JavaPairDStream<Object, Object> max = stream.mapToPair(record -> new Tuple2<>(record.key(), record.value()));
max.count();
max.print();
ssc.start();
}
我收到一条错误消息：
18/02/10 16:57:08 ERROR streaming.StreamingContext: Error starting the context, marking it as stopped
org.apache.kafka.common.KafkaException: Failed to construct kafka consumer
at org.apache.kafka.clients.consumer.KafkaConsumer.<init>(KafkaConsumer.java:703)
at org.apache.kafka.clients.consumer.KafkaConsumer.<init>(KafkaConsumer.java:553)
at org.apache.kafka.clients.consumer.KafkaConsumer.<init>(KafkaConsumer.java:536)
at org.apache.spark.streaming.kafka010.Subscribe.onStart(ConsumerStrategy.scala:83)
at org.apache.spark.streaming.kafka010.DirectKafkaInputDStream.consumer(DirectKafkaInputDStream.scala:75)
at org.apache.spark.streaming.kafka010.DirectKafkaInputDStream.start(DirectKafkaInputDStream.scala:243)
at org.apache.spark.streaming.DStreamGraph$$anonfun$start$5.apply(DStreamGraph.scala:49)
at org.apache.spark.streaming.DStreamGraph$$anonfun$start$5.apply(DStreamGraph.scala:49)
at scala.collection.parallel.mutable.ParArray$ParArrayIterator.foreach_quick(ParArray.scala:143)
at scala.collection.parallel.mutable.ParArray$ParArrayIterator.foreach(ParArray.scala:136)
at scala.collection.parallel.ParIterableLike$Foreach.leaf(ParIterableLike.scala:972)
at scala.collection.parallel.Task$$anonfun$tryLeaf$1.apply$mcV$sp(Tasks.scala:49)
at scala.collection.parallel.Task$$anonfun$tryLeaf$1.apply(Tasks.scala:48)
at scala.collection.parallel.Task$$anonfun$tryLeaf$1.apply(Tasks.scala:48)
at scala.collection.parallel.Task$class.tryLeaf(Tasks.scala:51)
at scala.collection.parallel.ParIterableLike$Foreach.tryLeaf(ParIterableLike.scala:969)
at scala.collection.parallel.AdaptiveWorkStealingTasks$WrappedTask$class.compute(Tasks.scala:152)
at scala.collection.parallel.AdaptiveWorkStealingForkJoinTasks$WrappedTask.compute(Tasks.scala:443)
at scala.concurrent.forkjoin.RecursiveAction.exec(RecursiveAction.java:160)
at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
at ... run in separate thread using org.apache.spark.util.ThreadUtils ... ()
at org.apache.spark.streaming.StreamingContext.liftedTree1$1(StreamingContext.scala:578)
at org.apache.spark.streaming.StreamingContext.start(StreamingContext.scala:572)
at org.apache.spark.streaming.api.java.JavaStreamingContext.start(JavaStreamingContext.scala:556)
at org.kafkaConnection2.main(kafkaConnection2.java:50)
Caused by: org.apache.kafka.common.KafkaException: com.fasterxml.jackson.databind.deser.std.StringDeserializer is not an instance of org.apache.kafka.common.serialization.Deserializer
at org.apache.kafka.common.config.AbstractConfig.getConfiguredInstance(AbstractConfig.java:205)
at org.apache.kafka.clients.consumer.KafkaConsumer.<init>(KafkaConsumer.java:624)
at org.apache.kafka.clients.consumer.KafkaConsumer.<init>(KafkaConsumer.java:553)
at org.apache.kafka.clients.consumer.KafkaConsumer.<init>(KafkaConsumer.java:536)
at org.apache.spark.streaming.kafka010.Subscribe.onStart(ConsumerStrategy.scala:83)
at org.apache.spark.streaming.kafka010.DirectKafkaInputDStream.consumer(DirectKafkaInputDStream.scala:75)
at org.apache.spark.streaming.kafka010.DirectKafkaInputDStream.start(DirectKafkaInputDStream.scala:243)
at org.apache.spark.streaming.DStreamGraph$$anonfun$start$5.apply(DStreamGraph.scala:49)
at org.apache.spark.streaming.DStreamGraph$$anonfun$start$5.apply(DStreamGraph.scala:49)
at scala.collection.parallel.mutable.ParArray$ParArrayIterator.foreach_quick(ParArray.scala:143)
at scala.collection.parallel.mutable.ParArray$ParArrayIterator.foreach(ParArray.scala:136)
at scala.collection.parallel.ParIterableLike$Foreach.leaf(ParIterableLike.scala:972)
at scala.collection.parallel.Task$$anonfun$tryLeaf$1.apply$mcV$sp(Tasks.scala:49)
at scala.collection.parallel.Task$$anonfun$tryLeaf$1.apply(Tasks.scala:48)
at scala.collection.parallel.Task$$anonfun$tryLeaf$1.apply(Tasks.scala:48)
at scala.collection.parallel.Task$class.tryLeaf(Tasks.scala:51)
at scala.collection.parallel.ParIterableLike$Foreach.tryLeaf(ParIterableLike.scala:969)
at scala.collection.parallel.AdaptiveWorkStealingTasks$WrappedTask$class.compute(Tasks.scala:152)
at scala.collection.parallel.AdaptiveWorkStealingForkJoinTasks$WrappedTask.compute(Tasks.scala:443)
at scala.concurrent.forkjoin.RecursiveAction.exec(RecursiveAction.java:160)
at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
我的假设是，可以通过连接到kafka来设置错误或其他问题...
请不要对这个相当愚蠢的问题感到烦恼，但我才开始使用Spark和Kafka
尝试使用org.apache.kafka.common.serialization.stringdeserializer代替com.fasterxml.jackson.databind.deser.std.std.stringdeserialialia> 请访问org.apache.kafka.common.config.abstractconfig.getConfiguredInstance(AbstractConfig.java:205( atrg.apache.kafka.clients.consumer.kafkaconsumer。(kafkaconsumer.java:624( atorg.apache.kafka.clients.consumer.kafkaconsumer。(kafkaconsumer.java:553( atrg.apache.kafka.clients.consumer.kafkaconsumer。(kafkaconsumer.java:536( atorg.apache.spark.streaming.kafka010.subscribe.onstart(commuterStrategy.Scala：83( 在