我正在尝试使用camel将消息发送到kafka。我从camel git repo中获取了camel示例代码。我运行MessagePublisherClient.java并得到以下异常。我已在属性文件中配置了我的Kafka服务器名称，端口和主题详细信息。
为什么我收到此异常以及如何修复此异常。
如果我尝试使用camel 2.14.1版本并根据2.14.1进行代码更改。我能够推送消息。但是为什么最新版本会出错。
Camel Repo： https://github.com/apache/camel/tree/master/examples/camel-example-kafka
Java 1.8 骆驼：2.21.0
错误：
Message History
---------------------------------------------------------------------------------------------------------------------------------------
RouteId ProcessorId Processor Elapsed (ms)
[DirectToKafka ] [DirectToKafka ] [direct://kafkaStart ] [ 60017]
[DirectToKafka ] [to1 ] [kafka:{{producer.topic}} ] [ 60013]
Stacktrace
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org.apache.kafka.common.errors.TimeoutException: Failed to update metadata after 60000 ms.
Exception in thread "main" org.apache.camel.CamelExecutionException: Exception occurred during execution on the exchange: Exchange[ID-host-1513537490104-0-1]
at org.apache.camel.util.ObjectHelper.wrapCamelExecutionException(ObjectHelper.java:1846)
at org.apache.camel.util.ExchangeHelper.extractResultBody(ExchangeHelper.java:713)
at org.apache.camel.impl.DefaultProducerTemplate.extractResultBody(DefaultProducerTemplate.java:515)
at org.apache.camel.impl.DefaultProducerTemplate.extractResultBody(DefaultProducerTemplate.java:511)
at org.apache.camel.impl.DefaultProducerTemplate.sendBodyAndHeaders(DefaultProducerTemplate.java:259)
at org.apache.camel.impl.DefaultProducerTemplate.sendBodyAndHeaders(DefaultProducerTemplate.java:253)
at org.apache.camel.example.kafka.MessagePublisherClient.main(MessagePublisherClient.java:91)
Caused by: org.apache.kafka.common.errors.TimeoutException: Failed to update metadata after 60000 ms.