為了省去每次都建立spark物件，寫了一個基礎類SparkSessionBase，沒想到叢集丟擲異常：A master URL must be set in your configuration。原因就在於spark物件在main函式之外建立，driver就不會把這個spark物件分發到其他work節點上。

class SparkSessionBase {
    protected val spark:SparkSession =SparkSession.builder().enableHiveSupport().getOrCreate();
}

object ImportHiveData2Kafka
 
 extends SparkSessionBase {
    def main(args: Array[String]): Unit = {
        val topic = args(0)
        val dataType = args(1)
        val dataSourceType = args(2)
        var infos: Dataset[String] = null
        dataSourceType match {
            case "parquet" =>  {infos = spark.read.load(args(3
 
)).toJSON}
            case "hive" => {infos = spark.sql("select * from " + args(3) + " where dt='" + args(4) +"'").toJSON}
            case _  => null
        }
        infos.foreachPartition(info => importToKafka(topic, dataType, info.toList))
        spark.close()
    }
}