Its hard to help without any stacktrace associated
with UnsupportedOperationException.
On Thu, Oct 15, 2015 at 10:40 PM, Chandra Mohan, Ananda Vel Murugan <
ananda.muru...@honeywell.com> wrote:
> One of my co-worker(Yogesh) was trying to get this posted in spark mailing
> and it seems it did not get posted. So I am reposting it here. Please help.
>
>
>
>
>
> Hi,
>
> I am new to Spark and was trying to do some experiments with it.
>
>
>
> I had a JavaPairDStream<String, List<String>> RDD.
>
> I want to get the list of string from its previous state. For that I use
> updateStateByKey function as follows:
>
>
>
> final Function2<List<String>, Optional<List<String>>,
> Optional<List<String>>> updateFunc =
>
> new Function2<List<String>, Optional<List<String>>,
>
> Optional<List<String>>>() {
>
>
>
> public Optional<List<String>> call(List<String> arg0,
> Optional<List<String>> arg1) throws Exception {
>
> // TODO Auto-generated method stub
>
> if(arg1.toString()==null)
>
> return Optional.of(arg0);
>
> else {
>
> arg0.add(arg1.toString());
>
> return Optional.of(arg0);
>
> }
>
> }
>
> };
>
>
>
> I want the function to append the new list of string to the previous list
> and return the new list. But I am not able to do so. I am getting the "
> java.lang.UnsupportedOperationException" error.
>
> Can anyone which help me out in getting the desired output?
>
>
>
