Aws集成弹簧:无法下载文件夹中的文件

Question

下面的代码尝试从S3上的文件夹中下载一个文件。它正在使用下面的消息处理程序。

注意：下面的代码适用于放置在S3存储桶根目录中的文件。它不适用于放置在文件夹中的文件。

    @Bean
    @ServiceActivator(inputChannel = "s3Channel")
    public MessageHandler s3Handler() {
       ExpressionParser PARSER = new SpelExpressionParser();
       S3MessageHandler s3MessageHandler = new S3MessageHandler(amazonS3(), "test.queue", true);
       s3MessageHandler.setOutputChannel(this.channel);
       s3MessageHandler.setCommand(S3MessageHandler.Command.DOWNLOAD);
       s3MessageHandler.setKeyExpression(PARSER.parseExpression("payload instanceof T(java.io.File) ? payload.name : headers.key"));
       s3MessageHandler.setObjectAclExpression(new ValueExpression<>(CannedAccessControlList.PublicReadWrite));
       return s3MessageHandler;
}

使用有效载荷：

 Message<?> payload = MessageBuilder.withPayload(new File("test/s3testfile.xml")).build();
 this.s3ProcessChannel.send(payload);

以下堆栈跟踪发生在从下载带有文件夹的文件时。

org.springframework.messaging.MessageHandlingException: error occurred in message handler [s3MessageHandler]; nested exception is com.amazonaws.services.s3.model.AmazonS3Exception: Not Found (Service: Amazon S3; Status Code: 404; Error Code: 404 Not Found;)
        at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:139) ~[spring-integration-core-4.2.5.RELEASE.jar:na]
        at org.springframework.messaging.support.ExecutorSubscribableChannel$SendTask.run(ExecutorSubscribableChannel.java:135) ~[spring-messaging-4.2.5.RELEASE.jar:4.2.5.RELEASE]
        at org.springframework.messaging.support.ExecutorSubscribableChannel.sendInternal(ExecutorSubscribableChannel.java:91) ~[spring-messaging-4.2.5.RELEASE.jar:4.2.5.RELEASE]
        at org.springframework.messaging.support.AbstractMessageChannel.send(AbstractMessageChannel.java:117) ~[spring-messaging-4.2.5.RELEASE.jar:4.2.5.RELEASE]
        at org.springframework.messaging.support.AbstractMessageChannel.send(AbstractMessageChannel.java:104) ~[spring-messaging-4.2.5.RELEASE.jar:4.2.5.RELEASE]
        at com.rapid7.live.assessment.aws.inbound.channels.SqsAssessmentMessageChannel.send(SqsAssessmentMessageChannel.java:44) ~[classes/:na]
        at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:115) ~[spring-messaging-4.2.5.RELEASE.jar:4.2.5.RELEASE]
        at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:45) ~[spring-messaging-4.2.5.RELEASE.jar:4.2.5.RELEASE]
        at org.springframework.messaging.core.AbstractMessageSendingTemplate.send(AbstractMessageSendingTemplate.java:105) ~[spring-messaging-4.2.5.RELEASE.jar:4.2.5.RELEASE]
        at org.springframework.integration.endpoint.MessageProducerSupport.sendMessage(MessageProducerSupport.java:105) ~[spring-integration-core-4.2.5.RELEASE.jar:na]
        at org.springframework.integration.aws.inbound.SqsMessageDrivenChannelAdapter.access$400(SqsMessageDrivenChannelAdapter.java:53) ~[spring-integration-aws-1.0.0.M1.jar:na]
        at org.springframework.integration.aws.inbound.SqsMessageDrivenChannelAdapter$IntegrationQueueMessageHandler.handleMessageInternal(SqsMessageDrivenChannelAdapter.java:154) ~[spring-integration-aws-1.0.0.M1.jar:na]
        at org.springframework.messaging.handler.invocation.AbstractMethodMessageHandler.handleMessage(AbstractMethodMessageHandler.java:389) ~[spring-messaging-4.2.5.RELEASE.jar:4.2.5.RELEASE]
        at org.springframework.cloud.aws.messaging.listener.SimpleMessageListenerContainer.executeMessage(SimpleMessageListenerContainer.java:181) ~[spring-cloud-aws-messaging-1.1.0.RC1.jar:1.1.0.RC1]
        at org.springframework.cloud.aws.messaging.listener.SimpleMessageListenerContainer$MessageExecutor.run(SimpleMessageListenerContainer.java:314) ~[spring-cloud-aws-messaging-1.1.0.RC1.jar:1.1.0.RC1]
        at org.springframework.cloud.aws.messaging.listener.SimpleMessageListenerContainer$SignalExecutingRunnable.run(SimpleMessageListenerContainer.java:368) [spring-cloud-aws-messaging-1.1.0.RC1.jar:1.1.0.RC1]
        at org.springframework.core.task.SimpleAsyncTaskExecutor$ConcurrencyThrottlingRunnable.run(SimpleAsyncTaskExecutor.java:251) [spring-core-4.2.5.RELEASE.jar:4.2.5.RELEASE]

该文件确实存在于正确的存储桶中。

Answer 1

问题是File.getName()只返回文件名，没有任何父目录。

考虑将keyExpression更改为：

"payload instanceof T(java.io.File) ? payload.path : headers.key"

或者只是不回复File负载，而是始终在标头中指定正确的key。