尝试使用spring-integration-aws S3StreamingMessageSource轮询S3时使用NPE

我正在尝试按照以下示例（在流入站通道适配器下）使用S3StreamMessageSource轮询S3对象存储：https : //github.com/spring-projects/spring-integration-aws/tree/v1.1.0.RELEASE

@Bean
@InboundChannelAdapter(value = "s3Channel", poller = @Poller(fixedDelay = "15000", maxMessagesPerPoll = "1"))
public MessageSource<InputStream> s3InboundStreamingMessageSource() {
    S3StreamingMessageSource messageSource = new S3StreamingMessageSource(s3RemoteFileTemplate());
    messageSource.setRemoteDirectory(s3Bucket+"/INBOX/");
    messageSource.setFilter(new S3SimplePatternFileListFilter("test*"));
    messageSource.setFilter(new S3PersistentAcceptOnceFileListFilter(new SimpleMetadataStore(), "s3Stream"));
    return messageSource;
}

@Bean
@org.springframework.integration.annotation.Transformer(inputChannel = "s3Channel", outputChannel = "nullChannel")
public Transformer transformer() {
    return new StreamTransformer();
}

@Bean
public S3RemoteFileTemplate s3RemoteFileTemplate() {
    return new S3RemoteFileTemplate(new S3SessionFactory(amazonS3));
}

但每次我的应用启动时，都会引发NPE：

2018-01-24 23:25:42.243 ERROR 29808 --- [ask-scheduler-1] o.s.integration.handler.LoggingHandler   : org.springframework.messaging.MessagingException: nested exception is java.lang.NullPointerException
    at org.springframework.integration.endpoint.AbstractPollingEndpoint$Poller.lambda$run$0(AbstractPollingEndpoint.java:396)
    at org.springframework.integration.util.ErrorHandlingTaskExecutor.lambda$execute$0(ErrorHandlingTaskExecutor.java:53)
    at org.springframework.core.task.SyncTaskExecutor.execute(SyncTaskExecutor.java:50)
    at org.springframework.integration.util.ErrorHandlingTaskExecutor.execute(ErrorHandlingTaskExecutor.java:51)
    at org.springframework.integration.endpoint.AbstractPollingEndpoint$Poller.run(AbstractPollingEndpoint.java:373)
    at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54)
    at org.springframework.scheduling.concurrent.ReschedulingRunnable.run(ReschedulingRunnable.java:93)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
    at org.springframework.integration.json.SimpleJsonSerializer.toElement(SimpleJsonSerializer.java:92)
    at org.springframework.integration.json.SimpleJsonSerializer.toJson(SimpleJsonSerializer.java:74)
    at org.springframework.integration.file.remote.AbstractFileInfo.toJson(AbstractFileInfo.java:60)
    at org.springframework.integration.file.remote.AbstractRemoteFileStreamingMessageSource.doReceive(AbstractRemoteFileStreamingMessageSource.java:164)
    at org.springframework.integration.endpoint.AbstractMessageSource.receive(AbstractMessageSource.java:141)
    at org.springframework.integration.endpoint.SourcePollingChannelAdapter.receiveMessage(SourcePollingChannelAdapter.java:230)
    at org.springframework.integration.endpoint.AbstractPollingEndpoint.doPoll(AbstractPollingEndpoint.java:250)
    at org.springframework.integration.endpoint.AbstractPollingEndpoint$Poller.lambda$run$0(AbstractPollingEndpoint.java:379)
    ... 13 more

当我逐步处理引发异常的位置时，它位于S3FileInfo.getPermissions中的代码部分，并且看到UnsupportedOperationException“使用[AmazonS3.getObjectAcl（）]获得权限。”

我需要怎么做才能解决这个问题？我正在使用Spring Boot 1.5.9.RELEASE，spring-integration-aws 1.1.0.RELEASE，spring-integration-core 5.0.0.RELEASE