error: value foreach is not a member of Object

spark3.0.1,scala 2.12使用foreachPartition报错：error: value foreach is not a member of Object

代码：

df.foreachPartition(partition=>partition.foreach(println))

报错:
value foreach is not a member of Object
    df.foreachPartition(partition=>partition.foreach(println))

这个报错看不出什么东西，因为还不是真正的错误信息，将代码改为：

df.foreachPartition(partition=>println(1))

报错：

ambiguous reference to overloaded definition,
both method foreachPartition in class Dataset of type (func: org.apache.spark.api.java.function.ForeachPartitionFunction[org.apache.spark.sql.Row])Unit
and  method foreachPartition in class Dataset of type (f: Iterator[org.apache.spark.sql.Row] => Unit)Unit
match argument types (Object => Unit)
   df.foreachPartition(partition=>println(1))

这里说模糊引用了重载定义的方法foreachPartition，那我们就显示的指定foreachPartition里面的函数即可

将代码改为：

 df.foreachPartition((partition:Iterator[Row])=>{
         partition.foreach(println)
    })

执行成功！