I have a similar situation in an app of mine. I implemented a custom ML Transformer that wraps the Jackson ObjectMapper - this gives you full control over how your custom entities / structs are serialized.
> On Mar 11, 2016, at 11:53 AM, Caires Vinicius <caire...@gmail.com> wrote: > > Hmm. I think my problem is a little more complex. I'm using > https://github.com/databricks/spark-redshift > <https://github.com/databricks/spark-redshift> and when I read from JSON file > I got this schema. > > root > |-- app: string (nullable = true) > > |-- ct: long (nullable = true) > > |-- event: struct (nullable = true) > > | |-- attributes: struct (nullable = true) > > | | |-- account: string (nullable = true) > > | | |-- accountEmail: string (nullable = true) > > > | | |-- accountId: string (nullable = true) > > > > I want to transform the Column event into String (formatted as JSON). > > I was trying to use udf but without success. > > > On Fri, Mar 11, 2016 at 1:53 PM Tristan Nixon <st...@memeticlabs.org > <mailto:st...@memeticlabs.org>> wrote: > Have you looked at DataFrame.write.json( path )? > https://spark.apache.org/docs/latest/api/scala/index.html#org.apache.spark.sql.DataFrameWriter > > <https://spark.apache.org/docs/latest/api/scala/index.html#org.apache.spark.sql.DataFrameWriter> > > > On Mar 11, 2016, at 7:15 AM, Caires Vinicius <caire...@gmail.com > > <mailto:caire...@gmail.com>> wrote: > > > > I have one DataFrame with nested StructField and I want to convert to JSON > > String. There is anyway to accomplish this? >