19/01/03 15:30:54 ERROR StreamingContext: Error starting the context, marking it as stopped
java.lang.IllegalArgumentException: requirement failed: No output operations registered, so nothing to execute
	at scala.Predef$.require(Predef.scala:233)
	at org.apache.spark.streaming.DStreamGraph.validate(DStreamGraph.scala:161)
	at org.apache.spark.streaming.StreamingContext.validate(StreamingContext.scala:542)
	at org.apache.spark.streaming.StreamingContext.liftedTree1$1(StreamingContext.scala:601)
	at org.apache.spark.streaming.StreamingContext.start(StreamingContext.scala:600)
	at SparkStreamingAndKafka$.main(SparkStreamingAndKafka.scala:55)
	at SparkStreamingAndKafka.main(SparkStreamingAndKafka.scala)
Exception in thread "main" java.lang.IllegalArgumentException: requirement failed: No output operations registered, so nothing to execute
	at scala.Predef$.require(Predef.scala:233)
	at org.apache.spark.streaming.DStreamGraph.validate(DStreamGraph.scala:161)
	at org.apache.spark.streaming.StreamingContext.validate(StreamingContext.scala:542)
	at org.apache.spark.streaming.StreamingContext.liftedTree1$1(StreamingContext.scala:601)
	at org.apache.spark.streaming.StreamingContext.start(StreamingContext.scala:600)
	at SparkStreamingAndKafka$.main(SparkStreamingAndKafka.scala:55)
	at SparkStreamingAndKafka.main(SparkStreamingAndKafka.scala)

解决原因：没有触发DStream需要的aciton
解决方法：使用以下方法之一触发：

print()
foreachRDD()
saveAsObjectFiles()
saveAsTextFiles()
saveAsHadoopFiles()

这个是kafka receiver出的错

https://blog.csdn.net/wzq294328238/article/details/46045189