在Kafka流上為窗口數據創建SerDes

Question

我在創建要與正在聚合的數據一起使用的SerDes時遇到一些麻煩，並且需要通過'.to（）'發送到另一個主題，但是，我需要為窗口數據創建SerDes，而我我不確定該怎么做。

Answer 1

我們可以通過以下方式為窗口數據創建Serilizer和DeSerilizer。

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);

下面給出了窗口數據中Serilizer / DeSerilizer的使用。

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");

我建議您仔細閱讀以下內容以獲得更多信息。

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