在Kafka流上为窗口数据创建SerDes

Question

我在创建要与正在聚合的数据一起使用的SerDes时遇到一些麻烦，并且需要通过'.to（）'发送到另一个主题，但是，我需要为窗口数据创建SerDes，而我我不确定该怎么做。

Answer 1

We can create the Serilizer and DeSerilizer for windowed data in the following ways.

StringSerializer stringSerializer = new StringSerializer();
StringDeserializer stringDeserializer = new StringDeserializer();
Serde<String> stringSerde = Serdes.serdeFrom(stringSerializer,stringDeserializer);

WindowedSerializer<String> windowedSerializer = new WindowedSerializer<>(stringSerializer);
WindowedDeserializer<String> windowedDeserializer = new WindowedDeserializer<>(stringDeserializer);
Serde<Windowed<String>> windowedSerde = Serdes.serdeFrom(windowedSerializer,windowedDeserializer);

Use of Serilizer/DeSerilizer in the windowed data is given below.

KStream<String,StockTransaction> transactionKStream =  kStreamBuilder.stream(stringSerde,transactionSerde,"stocks");

transactionKStream.map((k,v)-> new KeyValue<>(v.getSymbol(),v))
                              .through(stringSerde, transactionSerde,"stocks-out")
                              .groupBy((k,v) -> k, stringSerde, transactionSerde)
                              .aggregate(StockTransactionCollector::new,
                                   (k, v, stockTransactionCollector) -> stockTransactionCollector.add(v),
                                   TimeWindows.of(10000),
                                   collectorSerde, "stock-summaries")
                    .to(windowedSerde,collectorSerde,"transaction-summary");

I would suggest you to go through the following content to get more information.

https://www.programcreek.com/java-api-examples/index.php?api=org.apache.kafka.streams.kstream.internals.WindowedSerializer