我有一个SFTP路由（在Spring XML中），它的from路径结束于一个每天变化的目录（即/yyyyMMdd），当autoCreate=true或路由开始时目录存在时一切都很好。但如果目录不存在，则不允许我创建目录！
当目录存在时，路由会获取文件并自行终止。
当dir不存在时，路由将永久轮询并发出警告（即org.apache.camel.component.file.GenericFileOperationFailedException: Cannot change directory to: 20160917），并且永不停止。
我如何避免这种行为（例如，将警告转换为空消息或异常或...）？我已经做了一些实验，使用startingDirectoryMustExist，consumer.bridgeErrorHandler和许多其他方法，但都没有成功。
简化的路由（在开始之前，用实际日期填充elmu.sftp.importDir属性）：

<from
        uri="sftp://{{elmu.sftp.host}}:{{elmu.sftp.port}}{{elmu.sftp.importDir}}?username={{elmu.sftp.userName}}&amp;password={{elmu.sftp.password}}&amp;
        autoCreate=false&amp;preferredAuthentications=password&amp;binary=true&amp;include={{elmu.importMask}}&amp;initialDelay=100&amp;
        noop=true&amp;sortBy=file:name&amp;sendEmptyMessageWhenIdle=true"/>
    <choice>
        <when>
            <simple>${body} != null</simple>
            ... a lot of stuff ...
            <to uri="bean:shutdownRoute" />
        </when>
        <otherwise>
            <to uri="bean:shutdownRoute" />
        </otherwise>
    </choice>

如果使用directoryMustExist=true and startingDirectoryMustExist=true，则结果是一个无限循环（轮询），并显示以下警告：

08:30:14,658 WARN  SftpConsumer - Consumer Consumer[sftp://xxx.xxx.xx:22/DBHtest/ELMUteszt/Kiadott_adatok/20160918?autoCreate=false&binary=true&directoryMustExist=true&include=%5E.*%24&initialDelay=100&noop=true&password=xxxxxx&preferredAuthentications=password&sendEmptyMessageWhenIdle=true&sortBy=file%3Aname&startingDirectoryMustExist=true&username=xxx] failed polling endpoint: Endpoint[sftp://xxx:22/DBHtest/ELMUteszt/Kiadott_adatok/20160918?autoCreate=false&binary=true&directoryMustExist=true&include=%5E.*%24&initialDelay=100&noop=true&password=xxxxxx&preferredAuthentications=password&sendEmptyMessageWhenIdle=true&sortBy=file%3Aname&startingDirectoryMustExist=true&username=xxx]. Will try again at next poll. Caused by: [org.apache.camel.component.file.GenericFileOperationFailedException - Cannot change directory to: 20160918] 
org.apache.camel.component.file.GenericFileOperationFailedException: Cannot change directory to: 20160918
    at org.apache.camel.component.file.remote.SftpOperations.doChangeDirectory(SftpOperations.java:576)
    at org.apache.camel.component.file.remote.SftpOperations.changeCurrentDirectory(SftpOperations.java:564)
    at org.apache.camel.component.file.remote.SftpConsumer.doPollDirectory(SftpConsumer.java:107)
    at org.apache.camel.component.file.remote.SftpConsumer.pollDirectory(SftpConsumer.java:79)
    at org.apache.camel.component.file.GenericFileConsumer.poll(GenericFileConsumer.java:131)
    at org.apache.camel.impl.ScheduledPollConsumer.doRun(ScheduledPollConsumer.java:175)
    at org.apache.camel.impl.ScheduledPollConsumer.run(ScheduledPollConsumer.java:102)
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.util.concurrent.FutureTask.runAndReset(Unknown Source)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(Unknown Source)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: 2: No such file
    at com.jcraft.jsch.ChannelSftp.throwStatusError(ChannelSftp.java:2846)
    at com.jcraft.jsch.ChannelSftp._realpath(ChannelSftp.java:2340)
    at com.jcraft.jsch.ChannelSftp.cd(ChannelSftp.java:342)
    at org.apache.camel.component.file.remote.SftpOperations.doChangeDirectory(SftpOperations.java:574)
    ... 13 more

它不适用于stepwise=false：

11:52:19,210 WARN  SftpConsumer - Consumer Consumer[sftp://xxx:22/DBHtest/ELMUteszt/Kiadott_adatok/20160918?autoCreate=false&binary=true&directoryMustExist=true&include=%5E.*%24&initialDelay=100&noop=true&password=xxxxxx&preferredAuthentications=password&sendEmptyMessageWhenIdle=true&sortBy=file%3Aname&startingDirectoryMustExist=true&stepwise=false&username=xxx] failed polling endpoint: Endpoint[sftp://xxx:22/DBHtest/ELMUteszt/Kiadott_adatok/20160918?autoCreate=false&binary=true&directoryMustExist=true&include=%5E.*%24&initialDelay=100&noop=true&password=xxxxxx&preferredAuthentications=password&sendEmptyMessageWhenIdle=true&sortBy=file%3Aname&startingDirectoryMustExist=true&stepwise=false&username=xxx]. Will try again at next poll. Caused by: [org.apache.camel.component.file.GenericFileOperationFailedException - Cannot list directory: DBHtest/ELMUteszt/Kiadott_adatok/20160918] 
org.apache.camel.component.file.GenericFileOperationFailedException: Cannot list directory: DBHtest/ELMUteszt/Kiadott_adatok/20160918

更新（根据@ruffp的回答）：
我试着设置了一个自定义的PollingConsumerPollStrategy，但是我无法从它那里停止路由。只有第三行（注解行）停止了路由，但是我有几个路由，我不知道实际路由的名称。我该如何获得它？

@Override
    public boolean rollback(Consumer consumer, Endpoint endpoint, int retryCounter, Exception cause) throws Exception {
        consumer.getEndpoint().stop(); // 1
        consumer.stop();  // 2
        consumer.getEndpoint().getCamelContext().stopRoute(route???);  // 3
        return false;
    }