红帽全球峰会191.8. 使用带有 Kafka 消费者的手动提交
从 Camel 2.21 开始提供
默认情况下，Kafka 使用者将使用自动提交，其中偏移将使用给定间隔在后台自动提交。
如果要强制手动提交，您可以使用 Camel Exchange 中的 KafkaManualCommit API，存储在消息标头中。这需要将在 KafkaComponent 或端点上的选项 allowManualCommit 设置为 true 来打开手动提交，例如：
KafkaComponent kafka = new KafkaComponent();
kafka.setAllowManualCommit(true);
...
camelContext.addComponent("kafka", kafka);
KafkaComponent kafka = new KafkaComponent();
kafka.setAllowManualCommit(true);
...
camelContext.addComponent("kafka", kafka);
然后，您可以使用 Java 代码中的 KafkaManualCommit，如 Camel Processor ：
public void process(Exchange exchange) {
KafkaManualCommit manual =
exchange.getIn().getHeader(KafkaConstants.MANUAL_COMMIT, KafkaManualCommit.class);
manual.commitSync();
}
public void process(Exchange exchange) {
KafkaManualCommit manual =
exchange.getIn().getHeader(KafkaConstants.MANUAL_COMMIT, KafkaManualCommit.class);
manual.commitSync();
}这将强制进行同步提交，该提交将阻止在 Kafka 上确认提交，或者在抛出异常时失败。
如果要使用 KafkaManualCommit 的自定义实现，您可以在 KafkaComponent 上创建自定义实现实例上配置自定义 KafkaManualCommitFactory。
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