Haha, I feel the same pain with you man. On Tue, Oct 11, 2016 at 8:59 PM, Ali Akhtar <ali.rac...@gmail.com> wrote:
> Thanks. That filter() method is a good solution. But whenever I look at it, > I feel an empty spot in my heart which can only be filled by: > filter(Optional::isPresent) > > On Wed, Oct 12, 2016 at 12:15 AM, Guozhang Wang <wangg...@gmail.com> > wrote: > > > Ali, > > > > We are working on moving from Java7 to Java8 in Apache Kafka, and the > > Streams client is one of the motivations doing so. Stay tuned on the > > mailing list when it will come. > > > > Currently Streams won't automatically filter out null values for you > since > > in some other cases they may have semantic meanings and cannot be simply > > ignored; you can, though, apply a simple filter such like "filter((key, > > value) => value != null)" before your processor lambda operator, if it > > looks clearer in your code. > > > > Guozhang > > > > > > On Sun, Oct 9, 2016 at 3:14 PM, Ali Akhtar <ali.rac...@gmail.com> wrote: > > > > > It isn't a fatal error. It should be logged as a warning, and then the > > > stream should be continued w/ the next message. > > > > > > Checking for null is 'ok', in the sense that it gets the job done, but > > > after java 8's release, we really should be using optionals. > > > > > > Hopefully we can break compatibility w/ the bad old days soon and move > > into > > > the future. > > > > > > (If there's a way to do the null check automatically, i.e before > calling > > > the lambda, please let me know). > > > > > > On Sun, Oct 9, 2016 at 11:14 PM, Guozhang Wang <wangg...@gmail.com> > > wrote: > > > > > > > Ali, > > > > > > > > In your scenario, if serde fails to parse the bytes should that be > > > treated > > > > as a fatal failure or it is expected? > > > > > > > > In the former case, instead of returning a null I think it is better > to > > > > throw a runtime exception in order to let the whole client to stop > and > > > > notify the error; in the latter case, returning and checking null > looks > > > > fine to me. > > > > > > > > > > > > Guozhang > > > > > > > > On Fri, Oct 7, 2016 at 3:12 PM, Ali Akhtar <ali.rac...@gmail.com> > > wrote: > > > > > > > > > Hey G, > > > > > > > > > > Looks like the only difference is a valueSerde parameter. > > > > > > > > > > How does that prevent having to look for nulls in the consumer? > > > > > > > > > > E.g, I wrote a custom Serde which converts the messages (which are > > json > > > > > strings) into a Java class using Jackson. > > > > > > > > > > If the json parse fails, it sends back a null. > > > > > > > > > > When I'm reading this stream, in my callback, how would I prevent > > > having > > > > to > > > > > check if the serialized value isn't null? > > > > > > > > > > On Sat, Oct 8, 2016 at 1:07 AM, Guozhang Wang <wangg...@gmail.com> > > > > wrote: > > > > > > > > > > > Hello Ali, > > > > > > > > > > > > We do have corresponding overloaded functions for most of > KStream / > > > > > KTable > > > > > > operators to avoid enforcing users to specify "null"; in these > > cases > > > > the > > > > > > default serdes specified in the configs are then used. For > example: > > > > > > > > > > > > <T> KTable<K, T> aggregate(Initializer<T> initializer, > > > > > > Aggregator<K, V, T> adder, > > > > > > Aggregator<K, V, T> subtractor, > > > > > > Serde<T> aggValueSerde, > > > > > > String storeName); > > > > > > > > > > > > /** > > > > > > * .. using default serializers and deserializers. > > > > > > */ > > > > > > <T> KTable<K, T> aggregate(Initializer<T> initializer, > > > > > > Aggregator<K, V, T> adder, > > > > > > Aggregator<K, V, T> subtractor, > > > > > > String storeName); > > > > > > > > > > > > > > > > > > > > > > > > Guozhang > > > > > > > > > > > > > > > > > > On Fri, Oct 7, 2016 at 9:20 AM, Michael Noll < > mich...@confluent.io > > > > > > > > wrote: > > > > > > > > > > > > > Ali, the Apache Kafka project still targets Java 7, which means > > we > > > > > can't > > > > > > > use Java 8 features just yet. > > > > > > > > > > > > > > FYI: There's on ongoing conversation about when Kafka would > move > > > from > > > > > > Java > > > > > > > 7 to Java 8. > > > > > > > > > > > > > > On Fri, Oct 7, 2016 at 6:14 PM, Ali Akhtar < > ali.rac...@gmail.com > > > > > > > > wrote: > > > > > > > > > > > > > > > Since we're using Java 8 in most cases anyway, Serdes / > > > > Serialiazers > > > > > > > should > > > > > > > > use options, to avoid having to deal with the lovely nulls. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > -- Guozhang > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > -- Guozhang > > > > > > > > > > > > > > > -- > > -- Guozhang > > > -- -- Guozhang
