Hi John,
It should work with a *null* return value.
In the java doc of DeserializationSchema#deserialize it says that
> *@return The deserialized message as an object (null if the message cannot
> be deserialized).*
I also checked the Kafka fetcher in Flink and it can correctly handle a
null deserialized record.
Just pay attention to also not make *DeserializationSchema#isEndOfStream* throw
errors on a null record provided.
Thanks,
Zhu Zhu
John Smith <java.dev....@gmail.com> 于2019年10月12日周六 上午5:36写道：
> Hi using Flink 1.8.0.
>
> I am ingesting data from Kafka, unfortunately for the time being I have
> not looked into using the schema registry.
>
> So for now I would like to write a simple deserialization schema that
> discards the data if deserialization fails.
>
> The other option is to do in flat map with markers and split to dead
> letter queue, but I'm not too concerned about that for now.
>
> Is it ok to just return null if deserialization fails?
>
> @Override
> public MyObject deserialize(byte[] message) {
> try {
> return MyDecoder.decode(message));
> } catch (IOException ex) {
> logger.warn("Failed to decode message.", ex);
> return null;
> }
> }
>
>
