红帽全球峰会191.8. 使用 Kafka consumer 的手动提交
可作为 Camel 2.21 可用
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自动提交到后台。
如果要强制进行手动提交，您可以使用 Camel Exchange 中的 KafkaManualCommit API，存储在消息标头中。这需要通过在 KafkaComponent 或 端点上将选项 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，您可以使用来自 Java 代码的 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();
}这将强制一个同步提交，该提交将阻止，直到在 Kafka 上确认提交被确认，或者是否引发异常。
如果要使用 KafkaManualCommit 的自定义实现，那么您可以在创建自定义实施的 KafkaComponent 上配置自定义 KafkaManualCommitFactory。
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