Thanks Aljoscha, that works!
I tried passing values to base class constructor. Modifying the previous
example slightly:
class Base(var a: Int)
class X(b: Int) extends Base(b) {
this() { this(0) }
}
The code runs (even without Kryo) but compiler complains about b being
immutable.
> On 23 Sep 2015, at 15:02, Aljoscha Krettek <[email protected]> wrote:
>
> Hi Jack,
> Stephan is right, this should work. Unfortunately the TypeAnalyzer does not
> correctly detect that it cannot treat your Id class as a Pojo. I will add a
> Jira issue for that. For the time being you can use this command to force the
> system to use Kryo:
>
> env.getConfig.enableForceKryo();
>
> I hope this helps.
>
> Regards,
> Aljoscha
>
>
>> On Wed, 23 Sep 2015 at 13:37 Stephan Ewen <[email protected]> wrote:
>> Hi Jack!
>>
>> This should be supported, there is no strict requirement for mutable types.
>>
>> The POJO rules apply only if you want to use the "by-field-name" addressing
>> for keys. In Scala, you should be able to use case classes as well, even if
>> they are immutable.
>>
>> Can you post the exception that you get?
>>
>> Greetings,
>> Stephan
>>
>>
>>> On Wed, Sep 23, 2015 at 1:29 PM, Jack <[email protected]> wrote:
>>> Hi,
>>>
>>> I'm having trouble integrating existing Scala code with Flink, due to
>>> POJO-only requirement.
>>>
>>> We're using AnyVal heavily for type safety, and immutable classes as a
>>> default. For example, the following does not work:
>>>
>>> object Test {
>>> class Id(val underlying: Int) extends AnyVal
>>>
>>> class X(var id: Id) {
>>> def this() { this(new Id(0)) }
>>> }
>>>
>>> class MySource extends SourceFunction[X] {
>>> def run(ctx: SourceFunction.SourceContext[X]) {
>>> ctx.collect(new X(new Id(1)))
>>> }
>>> def cancel() {}
>>> }
>>>
>>> def main(args: Array[String]) {
>>> val env = StreamExecutionContext.getExecutionContext
>>> env.addSource(new MySource).print
>>> env.execute("Test")
>>> }
>>> }
>>>
>>> Currently I'm thinking that I would need to have duplicate classes and code
>>> for Flint and for non-Flint code, or somehow use immutable interfaces for
>>> non-Flint code. Both ways are expensive in terms of development time.
>>>
>>> Would you have any guidance on how to integrate Flink with a code base that
>>> has immutability as a norm?
>>>
>>> Thanks
