spring.cloud.stream.bindings.input.group=so8400replay
spring.cloud.stream.bindings.input.destination=error.so8400out.so8400

spring.cloud.stream.bindings.output.destination=so8400out

spring.cloud.stream.bindings.parkingLot.destination=so8400in.parkingLot

spring.cloud.stream.kafka.binder.configuration.auto.offset.reset=earliest

spring.cloud.stream.kafka.binder.headers=x-retries

@SpringBootApplication
public class ReRouteDlqKApplication implements CommandLineRunner {

    private static final String X_RETRIES_HEADER = "x-retries";

    public static void main(String[] args) {
        SpringApplication.run(ReRouteDlqKApplication.class, args).close();
    }

    private final AtomicInteger processed = new AtomicInteger();

    @Autowired
    private StreamBridge streamBridge;

    @Bean
    public Function<Message<?>, Message<?>> reRoute() {
        return failed -> {
            processed.incrementAndGet();
            Integer retries = failed.getHeaders().get(X_RETRIES_HEADER, Integer.class);
            if (retries == null) {
                System.out.println("First retry for " + failed);
                return MessageBuilder.fromMessage(failed)
                        .setHeader(X_RETRIES_HEADER, 1)
                        .setHeader(BinderHeaders.PARTITION_OVERRIDE,
                                failed.getHeaders().get(KafkaHeaders.RECEIVED_PARTITION_ID))
                        .build();
            }
            else if (retries < 3) {
                System.out.println("Another retry for " + failed);
                return MessageBuilder.fromMessage(failed)
                        .setHeader(X_RETRIES_HEADER, retries + 1)
                        .setHeader(BinderHeaders.PARTITION_OVERRIDE,
                                failed.getHeaders().get(KafkaHeaders.RECEIVED_PARTITION_ID))
                        .build();
            }
            else {
                System.out.println("Retries exhausted for " + failed);
                streamBridge.send("parkingLot", MessageBuilder.fromMessage(failed)
                    .setHeader(BinderHeaders.PARTITION_OVERRIDE,
                            failed.getHeaders().get(KafkaHeaders.RECEIVED_PARTITION_ID))
                    .build());
            }
            return null;
        };
    }

    @Override
    public void run(String... args) throws Exception {
        while (true) {
            int count = this.processed.get();
            Thread.sleep(5000);
            if (count == this.processed.get()) {
                System.out.println("Idle, exiting");
                return;
            }
        }
    }
}

@SpringBootApplication
public class SimpleConsumerApplication {

    @Bean
    public java.util.function.Consumer<KStream<Object, String>> process() {

        return input ->
                input.foreach((key, value) -> {
                    System.out.println("Key: " + key + " Value: " + value);
                });
    }
}

@Component(name = "process")
public class SimpleConsumer implements java.util.function.Consumer<KStream<Object, String>> {

    @Override
    public void accept(KStream<Object, String> input) {
        input.foreach((key, value) -> {
            System.out.println("Key: " + key + " Value: " + value);
        });
    }
}

java -jar kstream-consumer-app.jar --spring.cloud.stream.bindings.process-in-0.destination=my-topic

@SpringBootApplication
public class WordCountProcessorApplication {

  @Bean
  public Function<KStream<Object, String>, KStream<?, WordCount>> process() {

    return input -> input
                .flatMapValues(value -> Arrays.asList(value.toLowerCase().split("\\W+")))
                .map((key, value) -> new KeyValue<>(value, value))
                .groupByKey(Serialized.with(Serdes.String(), Serdes.String()))
                .windowedBy(TimeWindows.of(5000))
                .count(Materialized.as("word-counts-state-store"))
                .toStream()
                .map((key, value) -> new KeyValue<>(key.key(), new WordCount(key.key(), value,
                        new Date(key.window().start()), new Date(key.window().end()))));
  }

	public static void main(String[] args) {
		SpringApplication.run(WordCountProcessorApplication.class, args);
	}
}

java -jar wordcount-processor.jar --spring.cloud.stream.bindings.process-in-0.destination=words --spring.cloud.stream.bindings.process-out-0.destination=counts

@Bean
public java.util.function.Function<KStream<Object, String>, KStream<Object, String>> process() {
   ...
}

@Bean
public java.util.function.Consumer<KStream<Object, String>> anotherProcess() {
  ...
}

@Bean
public java.util.function.BiFunction<KStream<Object, String>, KTable<Integer, String>, KStream<Object, String>> yetAnotherProcess() {
   ...
}

@Bean
public java.util.function.Consumer<KStream<Object, String>> process() {
   ...
}

@Bean
public java.util.function.Consumer<KStream<Object, String>> anotherProcess() {
  ...
}

@Bean
public BiFunction<KStream<String, Long>, KTable<String, String>, KStream<String, Long>> process() {
...
}

@Bean
public Serde<Foo> customSerde() {
 ...
}

@Bean
public Function<KStream<String, Foo>, KStream<String, Foo>> process() {
}

@Bean
public BiFunction<KStream<CustomKey, AvroIn1>, KTable<CustomKey, AvroIn2>, KStream<CustomKey, AvroOutput>> process() {...}

spring.cloud.stream.kafka.streams.bindings.process-in-0.consumer.keySerde=CustomKeySerde
spring.cloud.stream.kafka.streams.bindings.process-in-0.consumer.valueSerde=io.confluent.kafka.streams.serdes.avro.SpecificAvroSerde

spring.cloud.stream.kafka.streams.bindings.process-in-1.consumer.keySerde=CustomKeySerde
spring.cloud.stream.kafka.streams.bindings.process-in-1.consumer.valueSerde=io.confluent.kafka.streams.serdes.avro.SpecificAvroSerde

spring.cloud.stream.kafka.streams.binder.configuration.default.key.serde
spring.cloud.stream.kafka.streams.binder.configuration.default.value.serde

spring.cloud.stream.bindings.process-in-0.contentType

spring.cloud.stream.kafka.streams.bindings.process-out-0.producer.keySerde=CustomKeySerde
spring.cloud.stream.kafka.streams.bindings.process-out-0.producer.valueSerde=io.confluent.kafka.streams.serdes.avro.SpecificAvroSerde

spring.cloud.stream.bindings.process-out-0.contentType

spring.cloud.stream.kafka.streams.binder.deserializationExceptionHandler: logAndContinue

spring.cloud.stream.kafka.streams.binder.deserializationExceptionHandler: logAndFail

spring.cloud.stream.kafka.streams.binder.deserializationExceptionHandler: sendToDlq

@Bean
public DlqDestinationResolver dlqDestinationResolver() {
    return (rec, ex) -> {
        if (rec.topic().equals("word1")) {
            return "topic1-dlq";
        }
        else {
            return "topic2-dlq";
        }
    };
}

spring.cloud.stream.kafka.streams.bindings.process-in-0.consumer.dlqName: custom-dlq (Change the binding name accordingly)

@Bean
public BiFunction<KStream<String, Long>, KTable<String, String>, KStream<String, Long>> process() {
...
}

@Bean
public DlqPartitionFunction partitionFunction() {
    return (group, record, ex) -> 0;
}

public <K> KeyQueryMetadata getKeyQueryMetadata(String store, K key, Serializer<K> serializer)

public <K> KafkaStreams getKafkaStreams(String store, K key, Serializer<K> serializer)

StoreQueryParameters<T> customize(StoreQueryParameters<T> storeQueryParameters);

@Bean
public StreamsBuilderFactoryBeanCustomizer customizer() {
    return fb -> {
        try {
            final StreamsBuilder streamsBuilder = fb.getObject();
            streamsBuilder.addGlobalStore(...);
        }
        catch (Exception e) {

        }
    };
}

@Bean
public StreamsBuilderFactoryBeanCustomizer customizer() {
    return fb -> {
        fb.getStreamsConfiguration().put(StreamsConfig.DEFAULT_PRODUCTION_EXCEPTION_HANDLER_CLASS_CONFIG,
                            CustomProductionExceptionHandler.class);
    };
}

spring.cloud.stream.kafka.streams.binder.configuration.default.key.serde=org.apache.kafka.common.serialization.Serdes$StringSerde
spring.cloud.stream.kafka.streams.binder.configuration.default.value.serde=org.apache.kafka.common.serialization.Serdes$StringSerde
spring.cloud.stream.kafka.streams.binder.configuration.commit.interval.ms=1000

@Bean
public Consumer<byte[]> processData() {
  return s -> {
     throw new RuntimeException();
  };
}

spring.cloud.stream:
  bindings:
   processData-in-0:
     group: my-group
     destination: input-topic
 kafka:
   bindings:
     processData-in-0:
       consumer:
         enableDlq: true
         dlqName: input-topic-dlq

@Bean
public Consumer<String> processData() {
  return s -> {
     throw new RuntimeException();
  };
}

spring.cloud.stream:
  bindings:
   processData-in-0:
     group: my-group
     destination: input-topic
 kafka:
   bindings:
     processData-in-0:
       consumer:
         enableDlq: true
         dlqName: input-topic-dlq
         dlqProducerProperties:
           configuration:
             value.serializer: org.apache.kafka.common.serialization.StringSerializer

spring.cloud.stream.bindings.processData-in-0.consumer.maxAtttempts
spring.cloud.stream.bindings.processData-in-0.consumer.backOffInitialInterval
spring.cloud.stream.bindings.processData-in-0.consumer.backOffMultipler
spring.cloud.stream.bindings.processData-in-0.consumer.backOffMaxInterval

spring.cloud.stream.bindings.processData-in-0.consumer.retryableExceptions.java.lang.IllegalStateException=true
spring.cloud.stream.bindings.processData-in-0.consumer.retryableExceptions.java.lang.IllegalArgumentException=false

spring.cloud.stream.bindings.processData-in-0.consumer.defaultRetryable=false

spring.cloud.stream.bindings.processData-in-0.consumer.retry-template-name=<your-retry-template-bean-name>

@Bean
public Consumer<String> functionName() {
    return s -> {
        System.out.println(s);
    };
}

	@Bean
	public ListenerContainerCustomizer<AbstractMessageListenerContainer<byte[], byte[]>> customizer(DefaultErrorHandler errorHandler) {
		return (container, dest, group) -> {
			container.setCommonErrorHandler(errorHandler);
		};
	}

	@Bean
	public DefaultErrorHandler errorHandler(DeadLetterPublishingRecoverer deadLetterPublishingRecoverer) {
		return new DefaultErrorHandler(deadLetterPublishingRecoverer);
	}

	@Bean
	public DeadLetterPublishingRecoverer publisher(KafkaOperations bytesTemplate) {
		return new DeadLetterPublishingRecoverer(bytesTemplate);
	}

spring.cloud.stream:
  function:
    definition: functionName
  bindings:
    functionName-in-0:
      group: group-name
      destination: input-topic
      consumer:
       use-native-decoding: true
  kafka:
    bindings:
      functionName-in-0:
        consumer:
          enableDlq: true
          dlqName: dlq-topic
          dlqProducerProperties:
            configuration:
              value.serializer: org.apache.kafka.common.serialization.StringSerializer
          configuration:
            value.deserializer: org.springframework.kafka.support.serializer.ErrorHandlingDeserializer
            spring.deserializer.value.delegate.class: org.apache.kafka.common.serialization.StringDeserializer

/**
	 * Invoked when partitions are initially assigned or after a rebalance. Applications
	 * might only want to perform seek operations on an initial assignment. While the
	 * 'initial' argument is true for each thread (when concurrency is greater than 1),
	 * implementations should keep track of exactly which partitions have been sought.
	 * There is a race in that a rebalance could occur during startup and so a topic/
	 * partition that has been sought on one thread may be re-assigned to another
	 * thread and you may not wish to re-seek it at that time.
	 * @param bindingName the name of the binding.
	 * @param consumer the consumer.
	 * @param partitions the partitions.
	 * @param initial true if this is the initial assignment on the current thread.
	 */
	default void onPartitionsAssigned(String bindingName, Consumer<?, ?> consumer,
			Collection<TopicPartition> partitions, boolean initial) {
		// do nothing
	}

Partition   start offset

0           1000
1           2000
2           2000
3           1000

@Override
public void onPartitionsAssigned(String bindingName, Consumer<?, ?> consumer, Collection<TopicPartition> partitions, boolean initial) {

    Map<TopicPartition, Long> topicPartitionOffset = new HashMap<>();
    topicPartitionOffset.put(new TopicPartition("foo", 0), 1000L);
    topicPartitionOffset.put(new TopicPartition("foo", 1), 2000L);
    topicPartitionOffset.put(new TopicPartition("foo", 2), 2000L);
    topicPartitionOffset.put(new TopicPartition("foo", 3), 1000L);

    if (initial) {
        partitions.forEach(tp -> {
            if (topicPartitionOffset.containsKey(tp)) {
                final Long offset = topicPartitionOffset.get(tp);
                try {
                    consumer.seek(tp, offset);
                }
                catch (Exception e) {
                    // Handle exceptions carefully.
                }
            }
        });
    }
}

@Bean
public Consumer<Message<String>> myConsumer() {
    return msg -> {
        Acknowledgment acknowledgment = message.getHeaders().get(KafkaHeaders.ACKNOWLEDGMENT, Acknowledgment.class);
        if (acknowledgment != null) {
         System.out.println("Acknowledgment provided");
         acknowledgment.acknowledge();
        }
    };
}

@Bean
public Function<String, String> uppercase(){
...
}

spring.cloud.stream.function.bindings.uppercase-in-0=my-transformer-in
spring.cloud.stream.function.bindings.uppercase-out-0=my-transformer-out

@Bean
public BiFunction<KStream<String, Order>, KTable<String, Account>, KStream<String, EnrichedOrder>> processOrder() {
...
}

@Bean
public Supplier<Message<String>> supplier() {
    return () -> MessageBuilder.withPayload("foo").setHeader(KafkaHeaders.MESSAGE_KEY, "my-foo").build();
}

spring.cloud.stream.kafka.bindings.supplier-out-0.producer.messageKeyExpression=headers['my-special-key']

spring.cloud.stream.kafka.bindings.<binding-name>.producer.useNativeEncoding: true

spring.cloud.stream.kafka.bindings.<binding-name>.producer.configuration.key.serializer: org.apache.kafka.common.serialization.StringSerializer
spring.cloud.stream.kafka.bindings.<binding-name>.producer.configuration.value.serializer: org.apache.kafka.common.serialization.StringSerializer

spring.cloud.stream.kafka.binder.configuration.key.serializer: org.apache.kafka.common.serialization.StringSerializer
spring.cloud.stream.kafka.binder.configuration.value.serializer: org.apache.kafka.common.serialization.StringSerializer

spring.cloud.stream.kafka.bindings.<binding-name>.consumer.configuration.key.deserializer: org.apache.kafka.common.serialization.StringDeserializer
spring.cloud.stream.kafka.bindings.<binding-name>.producer.configuration.value.deserializer: org.apache.kafka.common.serialization.StringDeserializer

spring.cloud.stream.kafka.bindings.<binding-name>.consumer.useNativeDecoding: true

@Bean
public BiConsumer<KStream<Object, Object>, KTable<Object, Object>> myBiConsumer{
    (s, t) -> s.join(t, ...)
    ...
}

spring.cloud.stream.kafka.streams.bindings.myBiConsumer-in-0.consumer.startOffset: latest
spring.cloud.stream.kafka.streams.bindings.myBiConsumer-in-1.consumer.startOffset: latest

@Bean
	public Supplier<Message<String>> supplier() {
		return () -> MessageBuilder.withPayload("foo").setHeader(KafkaHeaders.MESSAGE_KEY, "my-foo").build();
	}

@Bean
	public MessageChannel fooRecordChannel() {
		return new DirectChannel();
	}

spring.cloud.stream.kafka.bindings.supplier-out-0.producer.recordMetadataChannel: fooRecordChannel

@Bean
public IntegrationFlow integrationFlow() {
    return f -> f.channel("fooRecordChannel")
                 .handle((payload, messageHeaders) -> payload);
}

@Bean
public Supplier<Message<String>> supply() {
    return () -> MessageBuilder.withPayload("foo").setHeader("foo", "bar").build();
}

@Bean
public Consumer<Message<String>> consume() {
    return s -> {
        final String foo = (String)s.getHeaders().get("foo");
        System.out.println(foo);
    };
}

@Bean
public KafkaHeaderMapper kafkaBinderHeaderMapper() {
    return new KafkaHeaderMapper() {
        @Override
        public void fromHeaders(MessageHeaders headers, Headers target) {

        }

        @Override
        public void toHeaders(Headers source, Map<String, Object> target) {

        }
    };
}

@Bean
public KafkaHeaderMapper kafkaBinderHeaderMapper() {
    return new KafkaHeaderMapper() {
        @Override
        public void fromHeaders(MessageHeaders headers, Headers target) {
            final String foo = (String) headers.get("foo");
            target.add("foo", foo.getBytes());
        }

        @Override
        public void toHeaders(Headers source, Map<String, Object> target) {
            final Header foo = source.lastHeader("foo");
			target.put("foo", new String(foo.value()));
        }
    }

@Bean
public Supplier<Message<String>> supply() {
    return () -> MessageBuilder.withPayload("foo").setHeader("Id", "my-id").build();
}

@Bean
public KafkaHeaderMapper kafkaBinderHeaderMapper1() {
    return new KafkaHeaderMapper() {
        @Override
        public void fromHeaders(MessageHeaders headers, Headers target) {
            final String myId = (String) headers.get("Id");
			target.add("Id", myId.getBytes());
        }

        @Override
        public void toHeaders(Headers source, Map<String, Object> target) {
            final Header Id = source.lastHeader("Id");
			target.put("Id", new String(Id.value()));
        }
    };
}

@Autowired
StreamBridge bridge;

@Bean
Consumer<String> input() {
    return str -> {
        System.out.println(str);
        this.bridge.send("left", str.toUpperCase());
        this.bridge.send("right", str.toLowerCase());
        if (str.equals("Fail")) {
            throw new RuntimeException("test");
        }
    };
}

@Bean
ListenerContainerCustomizer<AbstractMessageListenerContainer<?, ?>> customizer(BinderFactory binders) {
    return (container, dest, group) -> {
        ProducerFactory<byte[], byte[]> pf = ((KafkaMessageChannelBinder) binders.getBinder(null,
                MessageChannel.class)).getTransactionalProducerFactory();
        KafkaTemplate<byte[], byte[]> template = new KafkaTemplate<>(pf);
        DefaultAfterRollbackProcessor rollbackProcessor = rollbackProcessor(template);
        container.setAfterRollbackProcessor(rollbackProcessor);
    };
}

DefaultAfterRollbackProcessor rollbackProcessor(KafkaTemplate<byte[], byte[]> template) {
    return new DefaultAfterRollbackProcessor<>(
            new DeadLetterPublishingRecoverer(template), new FixedBackOff(2000L, 2L), template, true);
}

spring.cloud.stream.kafka.binder.transaction.transaction-id-prefix: tx-
spring.cloud.stream.kafka.binder.required-acks=all
spring.cloud.stream.bindings.input-in-0.group=foo
spring.cloud.stream.bindings.input-in-0.destination=input
spring.cloud.stream.bindings.left.destination=left
spring.cloud.stream.bindings.right.destination=right

spring.cloud.stream.kafka.bindings.input-in-0.consumer.maxAttempts=1

@Bean
public ApplicationRunner runner(KafkaTemplate<byte[], byte[]> template) {
    return args -> {
        System.in.read();
        template.send("input", "Fail".getBytes());
        template.send("input", "Good".getBytes());
    };
}

spring.cloud.stream.pollable-source: foo
spring.cloud.stream.bindings.foo-in-0.group: my-group

spring.cloud.stream.kafka.bindings.foo-in-0.consumer.configuration.client.id=${client.id}