spark org.apache.spark.SparkException: Task not serializable 报错求助

 
          Dataset<Row> dataFrame = sparkSession.sql(“select * from product”);
           dataFrame.toJavaRDD().foreachPartition(new VoidFunction<Iterator<Row>>() {
            private static final long serialVersionUID = 1L;
            @Override
            public void call(Iterator<Row> rows) throws Exception {
                try {
                   System.out.print("hello world");
                } catch (Exception e) {
                }
            }
        });执行的时候报错：
18/11/13 21:31:18 ERROR yarn.ApplicationMaster: User class threw exception: org.apache.spark.SparkException: Task not serializable
org.apache.spark.SparkException: Task not serializable
        at org.apache.spark.util.ClosureCleaner$.ensureSerializable(ClosureCleaner.scala:298)
        at org.apache.spark.util.ClosureCleaner$.org$apache$spark$util$ClosureCleaner$$clean(ClosureCleaner.scala:288)
        at org.apache.spark.util.ClosureCleaner$.clean(ClosureCleaner.scala:108)
        at org.apache.spark.SparkContext.clean(SparkContext.scala:2101)
        at org.apache.spark.rdd.RDD$$anonfun$foreachPartition$1.apply(RDD.scala:925)
        at org.apache.spark.rdd.RDD$$anonfun$foreachPartition$1.apply(RDD.scala:924)
        at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:151)
        at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:112)
        at org.apache.spark.rdd.RDD.withScope(RDD.scala:362)
        at org.apache.spark.rdd.RDD.foreachPartition(RDD.scala:924)
        at org.apache.spark.api.java.JavaRDDLike$class.foreachPartition(JavaRDDLike.scala:219)
        at org.apache.spark.api.java.AbstractJavaRDDLike.foreachPartition(JavaRDDLike.scala:45)
参照其他的帖子，我的函数里面没有引用其他任何外部变量，为什么还会有这种报错，百思不得其解，恳请大神指点