創建SparkStreamingContext
1)val conf=new SparkConf().setMaster("local[2]").setAppName("wordcount")
val streamContext=new StreamingContext(conf,Seconds(5))
2)val sps=new StreamingContext(new SparkContext(conf),Seconds(5))
//如果關閉的時候只想關閉StreamingContext不想關閉SparkContext則
sps.stop(false)