Joining Pojos

[Benjamin Wootton]

Hi All

I'm new to Flink.  I am having a lot of success but I'm struggling with Windowed joins over Pojos.

In a toy example I am trying to respond to flight delay events and pull some fields from flight details: 

flightDelaysStream
.map(new FlightDelaysMapper())
.join(flightDetailsStream)
.where( new FlightDelayKeySelector() )
.equalTo(new MyKeySelector() )
.window(TumblingEventTimeWindows.of(Time.seconds(10)))
.apply(new JF())
.print();

My problem is in the where and equalTo clauses.  I can't seem to specify a Key selector for flight details as the equalTo clause doesn't accept anything related to FlightDetails.  

All of the examples I can find online are Tuples.  Should this kind of thing be possible with Pojos?  Much prefer to stay in the domain objects if possible.

Thanks

Ben

[Zhenghua Gao]

POJO is available in KeySelector[1].

Could you provide more information about your problem? Version of Flink? Error messages?

[1] https://ci.apache.org/projects/flink/flink-docs-stable/dev/api_concepts.html#define-keys-using-key-selector-functions

On Mon, Sep 16, 2019 at 11:16 PM Benjamin Wootton <[hidden email]> wrote:

Hi All

I'm new to Flink.  I am having a lot of success but I'm struggling with Windowed joins over Pojos.

In a toy example I am trying to respond to flight delay events and pull some fields from flight details: 

flightDelaysStream
.map(new FlightDelaysMapper())
.join(flightDetailsStream)
.where( new FlightDelayKeySelector() )
.equalTo(new MyKeySelector() )
.window(TumblingEventTimeWindows.of(Time.seconds(10)))
.apply(new JF())
.print();

My problem is in the where and equalTo clauses.  I can't seem to specify a Key selector for flight details as the equalTo clause doesn't accept anything related to FlightDetails.  

All of the examples I can find online are Tuples.  Should this kind of thing be possible with Pojos?  Much prefer to stay in the domain objects if possible.

Thanks

Ben