我想聚合3个主题，但为了聚合策略的poc，我尝试聚合2个主题。
因此，我配置了以下驼峰路由：

@Override
public void configure() throws Exception {
CamelContext contexto = new DefaultCamelContext();
try{
    onException(SQLException.class, Exception.class)
            .handled(true)
            .maximumRedeliveries(1)
            .process(new CustomExceptionProcess());

    errorHandler(deadLetterChannel("file:data/error") // There is no file created 
            .maximumRedeliveries(3)
            .redeliveryDelay(5000));

    from("kafka:topic1") 
            .process(new ProcessTopic1()) // inside this process 
            .to("direct:agregador");

    from("kafka:topic2") 
            .process(new ProcessTopic2())
            .to("direct:agregador");

    from("direct:agregador")
            .aggregate(header("idAgregador"), new EstrategiaAgregador()) // implements AggregationStrategy
            .completionPredicate(predicadoTamanhoMinimo()) // This just to check if is there at least 2 objects before realease the aggregation.
            .eagerCheckCompletion()
            .to("direct:insereBanco")
            ;

    from("direct:insereBanco")
            .process(new ProcessoInsere());

}catch (Exception e){
    LOG.error("Error in the route: ", e);
}

主题1和主题2的过程是这样的：

// It's the same process for ProcessTopic1 and ProcessTopic2
@Override
public void process(Exchange exchange) throws Exception {

    if(!(exchange.getIn().getBody() instanceof Object1)){

        String someData = (String) exchange.getIn().getBody();

        JSONParser parser = new JSONParser();
        Object objeto = parser.parse(someData);
        JSONObject json = (JSONObject) objeto;

        ObjectMapper mapeadorObj = new ObjectMapper();
        Object1 someEntity = mapeadorObj.readValue(json.toString(), Object1.class);

        ProducerTemplate producerTemplate = exchange.getContext().createProducerTemplate();
        producerTemplate.sendBodyAndHeader("direct:agregador", someEntity, "idAgregador", someEntity.getId());
    }
}

但是，当我得到要聚合的第一条消息时，消息离开了（因为必须等待第二条消息），但是很快这个消息退出了，我得到了这个异常：

org.apache.camel.CamelExchangeException: Invalid correlation key. Exchange[ID-XXXX-1597437627634-0-1]
    at org.apache.camel.processor.aggregate.AggregateProcessor.doProcess(AggregateProcessor.java:302)
    at org.apache.camel.processor.aggregate.AggregateProcessor.process(AggregateProcessor.java:271)
    at org.apache.camel.management.InstrumentationProcessor.process(InstrumentationProcessor.java:76)
    at org.apache.camel.processor.RedeliveryErrorHandler.process(RedeliveryErrorHandler.java:548)
    at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:201)
    at org.apache.camel.processor.Pipeline.process(Pipeline.java:138)
    at org.apache.camel.processor.Pipeline.process(Pipeline.java:101)
    at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:201)
    at org.apache.camel.component.direct.DirectProducer.process(DirectProducer.java:76)
>>  at org.apache.camel.processor.SendProcessor.process(SendProcessor.java:148)
    at org.apache.camel.management.InstrumentationProcessor.process(InstrumentationProcessor.java:76)
    at org.apache.camel.processor.RedeliveryErrorHandler.process(RedeliveryErrorHandler.java:548)
    at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:201)
    at org.apache.camel.processor.Pipeline.process(Pipeline.java:138)
    at org.apache.camel.processor.Pipeline.process(Pipeline.java:101)
    at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:201)
    at org.apache.camel.processor.DelegateAsyncProcessor.process(DelegateAsyncProcessor.java:97)
>>  at org.apache.camel.component.kafka.KafkaConsumer$KafkaFetchRecords.doRun(KafkaConsumer.java:326)
    at org.apache.camel.component.kafka.KafkaConsumer$KafkaFetchRecords.run(KafkaConsumer.java:215)

有一件事是我还使用了一个kafka主题来发送消息，因为它出现在堆栈跟踪中，所以我不确定是否也需要设置kafka。