在使用Kafka流向Kafka上的主题生成消息时如何添加标题

Question

嘿，我正在使用kStreams向主题发送消息。我的留言是一个字符串。

我想向其中添加一些标头，以便最终系统可以根据标头过滤掉。

我试图在所有地方找到，但找不到可靠的答案

这是我正在使用的一些代码。

公共类处理器{     私有静态最终字符串APPLICATION_ID =“ output-actor”;

public void process() {
    KafkaStreams kafkaStreams = new KafkaStreams(topology(), config());
    kafkaStreams.start();
}

private Properties config() {
    return KafkaUtil.getStreamsApplicationProperties(APPLICATION_ID);
}

private Topology topology() {

    final Serde<String> stringSerde = Serdes.String();

    StreamsBuilder builder = new StreamsBuilder();

    KStream<String, Transaction> potaPi = builder.stream(inputTopic(), consumeTransactionResult())
             .filter(isNull())
             .filter(sourceSystemFilter())
             .filter(currentStateValidation())
             .mapValues(ormToPotapi())
             .filter(applyGLPSourceSystemFilter());

    potaPi.map(transactionToXMLString())
    .to(cintOutputTopic(), Produced.with(stringSerde, stringSerde));


    return builder.build();
}

private Predicate<String, Transaction> applyGLPSourceSystemFilter() {
    GLPSourceSystemFilter glpSourceSystemFilter = new GLPSourceSystemFilter();
    return new TransactionContainsGLPSource(glpSourceSystemFilter);
}

private String cintOutputTopic() {
    return SystemUtil.getEnvironmentVariable("CINT_OUTPUT_TOPIC", "prod-glp-se-customs-address-write");
}

private KeyValueMapper<String, Transaction, KeyValue<String, String>> transactionToXMLString() {
    return new TransactionToGLPXMLMapper();
}

private ValueMapper<TransactionResult, Transaction> ormToPotapi() {
    return new OrmToPotapiMapper();
}

private Predicate<String,TransactionResult> isNull() {
    return (k , v ) -> v != null;
}

private Predicate<String, TransactionResult> sourceSystemFilter() {
    return (key,
            transactionResult) -> ((null != transactionResult.getTransaction().getBundle().getItems() && transactionResult.getTransaction().getBundle().getItems().size() > 0) &&
            (transactionResult.getTransaction().getBundle().getItems().get(0).getSource()
                    .toString().equalsIgnoreCase("POTAPI/ASTA")));
}

private Predicate<String, TransactionResult> currentStateValidation() {
    return (key,
            transactionResult) -> (null != transactionResult.getTransaction().getBundle().getOrders() && transactionResult.getTransaction().getBundle().getItems().size() > 0);
}

private Consumed<String, TransactionResult> consumeTransactionResult() {
    Serde<String> keySerde = Serdes.String();
    Serde<TransactionResult> valueSerde = TransactionSerde.transactionResult();
    return Consumed.with(keySerde, valueSerde);
}

private String inputTopic() {
    return SystemUtil.getEnvironmentVariable("INPUT_TOPIC", "transaction-commit");
}

}