问集成Spark Streaming和Kafka，但会出现错误的符号引用错误？

EN

Error:scalac: bad symbolic reference. A signature in KafkaUtils.class refers to term kafka 
in package <root> which is not available. 
It may be completely missing from the current classpath, or the version on 
the classpath might be incompatible with the version used when compiling KafkaUtils.class.

object Kafka { 

  def main(args: Array[String]) { 
    val master = "local[*]" 
    val zkQuorum = "localhost:2181" 
    val group = "" 
    val topics = "test" 
    val numThreads = 1 

    val conf = new SparkConf().setAppName("Kafka") 
    val ssc = new StreamingContext(conf, Seconds(2)) 

    val topicpMap = topics.split(",").map((_, numThreads.toInt)).toMap 

    val lines = KafkaUtils.createStream(ssc, zkQuorum, group, topicpMap).map(_._2) 

    val words = lines.flatMap(_.split(" ")) 

    words.print() 

    ssc.start() 
    ssc.awaitTermination() 
  } 
}