我在Java8程序中运行以下行SparkConfsparkConf=newSparkConf();sparkConf.setAppName("testJob");sparkConf.setMaster("spark://blahblah:7077");SparkSessionsparkSession=SparkSession.builder().config(sparkConf).getOrCreate();SQLContextsqlContext=newSQLContext(sparkSession);Datasetds=sqlContext.sql("SHOWTABLES");我得