在这段时间之后，我设法解决了这个问题。为此，我遵循了springbean的创建过程，并检查了 FileStateRepository 我需要一个文件，所以我创建了一个文件bean并添加为构造函数arg。之后我加了一个 init-method="doStart" . 此方法加载一个文件（如果存在），如果不存在，它将创建该文件。

<endpoint id="event" uri="kafka:localhost:9092">
        <property key="topic" value="eventTopic4"/>
        <property key="brokers" value="localhost:9092"/>
        <property key="autoOffsetReset" value="earliest"/>
        <property key="offsetRepository" value="#myRepo2"/>
    </endpoint>

    <bean id="myFileOfMyRepo" class="java.io.File">
        <constructor-arg type="java.lang.String" value="C:\repoDat\repo.dat"/>
    </bean>

    <bean id="myRepo2" class="org.apache.camel.impl.FileStateRepository " factory-method="fileStateRepository" init-method="doStart">
        <constructor-arg ref="myFileOfMyRepo"/>
    </bean>

在这之后，我在git中看到了camel的kafkaconsumer的代码。

offsetRepository.getState(serializeOffsetKey(topicPartition));
    if (offsetState != null && !offsetState.isEmpty()) {
        // The state contains the last read offset so you need to seek from the next one
        long offset = deserializeOffsetValue(offsetState) + 1;
        log.debug("Resuming partition {} from offset {} from state", topicPartition.partition(), offset);
        consumer.seek(topicPartition, offset);
    }

用这个我设法从最后一个偏移量读出来。我希望 Camel 文档为Kafka添加这些额外的步骤。

重要的词是“repository”而不是“offset”：它不是一个整数值，但它是对bean的引用，用于指定偏移的持久化位置。
（非Spring）示例

// Create the repository in which the Kafka offsets will be persisted
FileStateRepository repository = FileStateRepository.fileStateRepository(new File("/path/to/repo.dat"));

// Bind this repository into the Camel registry
JndiRegistry registry = new JndiRegistry();
registry.bind("offsetRepo", repository);

// Configure the camel context
DefaultCamelContext camelContext = new DefaultCamelContext(registry);
camelContext.addRoutes(new RouteBuilder() {
    @Override
    public void configure() throws Exception {
        from("kafka:" + TOPIC + "?brokers=localhost:{{kafkaPort}}" +
                     "&groupId=A" +                            //
                     "&autoOffsetReset=earliest" +             // Ask to start from the beginning if we have unknown offset
                     "&offsetRepository=#offsetRepo")          // Keep the offsets in the previously configured repository
                .to("mock:result");
    }
});