org.apache.kafka.streams.kstream.TransformerSupplier Java Examples

public static void main(String[] args) throws Exception {


        StreamsConfig streamsConfig = new StreamsConfig(getProperties());
        Serde<String> stringSerde = Serdes.String();
        Serde<StockPerformance> stockPerformanceSerde = StreamsSerdes.StockPerformanceSerde();
        Serde<StockTransaction> stockTransactionSerde = StreamsSerdes.StockTransactionSerde();


        StreamsBuilder builder = new StreamsBuilder();

        String stocksStateStore = "stock-performance-store";
        double differentialThreshold = 0.05;

        TransformerSupplier<String, StockTransaction, KeyValue<String, List<KeyValue<String, StockPerformance>>>> transformerSupplier =
                () -> new StockPerformanceMultipleValuesTransformer(stocksStateStore, differentialThreshold);

        KeyValueBytesStoreSupplier storeSupplier = Stores.lruMap(stocksStateStore, 100);
        StoreBuilder<KeyValueStore<String, StockPerformance>> storeBuilder = Stores.keyValueStoreBuilder(storeSupplier, Serdes.String(), stockPerformanceSerde);

        builder.addStateStore(storeBuilder);

        builder.stream("stock-transactions", Consumed.with(stringSerde, stockTransactionSerde))
                .transform(transformerSupplier, stocksStateStore).flatMap((dummyKey,valueList) -> valueList)
                .print(Printed.<String, StockPerformance>toSysOut().withLabel("StockPerformance"));
                //.to(stringSerde, stockPerformanceSerde, "stock-performance");


        KafkaStreams kafkaStreams = new KafkaStreams(builder.build(), streamsConfig);
        MockDataProducer.produceStockTransactionsWithKeyFunction(50, 50, 25, StockTransaction::getSymbol);
        System.out.println("Stock Analysis KStream/Process API App Started");
        kafkaStreams.cleanUp();
        kafkaStreams.start();
        Thread.sleep(70000);
        System.out.println("Shutting down the Stock KStream/Process API Analysis App now");
        kafkaStreams.close();
        MockDataProducer.shutdown();
    }
 

TracingTransformerSupplier(KafkaStreamsTracing kafkaStreamsTracing,
  String spanName,
  TransformerSupplier<K, V, R> delegateTransformerSupplier) {
  this.kafkaStreamsTracing = kafkaStreamsTracing;
  this.spanName = spanName;
  this.delegateTransformerSupplier = delegateTransformerSupplier;
}
 

/**
 * Create a map transformer, similar to {@link KStream#map(KeyValueMapper)}, where its mapper
 * action will be recorded in a new span with the indicated name.
 *
 * <p>Simple example using Kafka Streams DSL:
 * <pre>{@code
 * StreamsBuilder builder = new StreamsBuilder();
 * builder.stream(inputTopic)
 *        .transform(kafkaStreamsTracing.map("myMap", (k, v) -> ...)
 *        .to(outputTopic);
 * }</pre>
 */
public <K, V, KR, VR> TransformerSupplier<K, V, KeyValue<KR, VR>> map(String spanName,
  KeyValueMapper<K, V, KeyValue<KR, VR>> mapper) {
  return new TracingTransformerSupplier<>(this, spanName, () ->
    new AbstractTracingTransformer<K, V, KeyValue<KR, VR>>() {
      @Override public KeyValue<KR, VR> transform(K key, V value) {
        return mapper.apply(key, value);
      }
    });
}
 

/**
 * Create a flatMap transformer, similar to {@link KStream#flatMap(KeyValueMapper)}, where its
 * mapper action will be recorded in a new span with the indicated name.
 *
 * <p>Simple example using Kafka Streams DSL:
 * <pre>{@code
 * StreamsBuilder builder = new StreamsBuilder();
 * builder.stream(inputTopic)
 *        .flatTransform(kafkaStreamsTracing.flatMap("myflatMap", (k, v) -> ...)
 *        .to(outputTopic);
 * }</pre>
 */
public <K, V, KR, VR> TransformerSupplier<K, V, Iterable<KeyValue<KR, VR>>> flatMap(
  String spanName,
  KeyValueMapper<K, V, Iterable<KeyValue<KR, VR>>> mapper) {
  return new TracingTransformerSupplier<>(this, spanName, () ->
    new AbstractTracingTransformer<K, V, Iterable<KeyValue<KR, VR>>>() {
      @Override public Iterable<KeyValue<KR, VR>> transform(K key, V value) {
        return mapper.apply(key, value);
      }
    });
}
 

/**
 * Create a tracing-decorated {@link TransformerSupplier}
 *
 * <p>Simple example using Kafka Streams DSL:
 * <pre>{@code
 * StreamsBuilder builder = new StreamsBuilder();
 * builder.stream(inputTopic)
 *        .transform(kafkaStreamsTracing.transformer("my-transformer", myTransformerSupplier)
 *        .to(outputTopic);
 * }</pre>
 */
public <K, V, R> TransformerSupplier<K, V, R> transformer(String spanName,
  TransformerSupplier<K, V, R> transformerSupplier) {
  return new TracingTransformerSupplier<>(this, spanName, transformerSupplier);
}
 

/**
 * Create a filter transformer.
 *
 * WARNING: this filter implementation uses the Streams transform API, meaning that
 * re-partitioning can occur if a key modifying operation like grouping or joining operation is
 * applied after this filter.
 *
 * In that case, consider using {@link #markAsFiltered(String, Predicate)} instead which uses
 * {@link ValueTransformerWithKey} API instead.
 *
 * <p>Simple example using Kafka Streams DSL:
 * <pre>{@code
 * StreamsBuilder builder = new StreamsBuilder();
 * builder.stream(inputTopic)
 *       .transform(kafkaStreamsTracing.filter("myFilter", (k, v) -> ...)
 *       .to(outputTopic);
 * }</pre>
 */
public <K, V> TransformerSupplier<K, V, KeyValue<K, V>> filter(String spanName,
  Predicate<K, V> predicate) {
  return new TracingFilterTransformerSupplier<>(this, spanName, predicate, false);
}
 

/**
 * Create a filterNot transformer.
 *
 * WARNING: this filter implementation uses the Streams transform API, meaning that
 * re-partitioning can occur if a key modifying operation like grouping or joining operation is
 * applied after this filter. In that case, consider using {@link #markAsNotFiltered(String,
 * Predicate)} instead which uses {@link ValueTransformerWithKey} API instead.
 *
 * <p>Simple example using Kafka Streams DSL:
 * <pre>{@code
 * StreamsBuilder builder = new StreamsBuilder();
 * builder.stream(inputTopic)
 *       .transform(kafkaStreamsTracing.filterNot("myFilter", (k, v) -> ...)
 *       .to(outputTopic);
 * }</pre>
 */
public <K, V> TransformerSupplier<K, V, KeyValue<K, V>> filterNot(String spanName,
  Predicate<K, V> predicate) {
  return new TracingFilterTransformerSupplier<>(this, spanName, predicate, true);
}