如何用Scala的akka.stream.alpakka.ftp列出SFTP文件？遇传输错误

代码片段 #

val ftpApi: FtpApi[SSHClient, SftpSettings]

val futureResult = ftpApi.ls(basePath = path, connectionSettings = settings)

错误日志 #

11:53:36.875 [sshj-Reader-/200.13.144.60:181] DEBUG net.schmizz.sshj.transport.TransportImpl - Setting active service to null-service
11:53:36.875 [sshj-Reader-/200.13.144.60:181] DEBUG net.schmizz.concurrent.Promise - Setting <<transport close>> to `SOME`
11:53:36.875 [sshj-Reader-/200.13.144.60:181] DEBUG net.schmizz.sshj.transport.Reader - Stopping
[ERROR] [02/27/2023 11:53:36.876] [default-akka.actor.default-blocking-io-dispatcher-21] [akka://default/system/Materializers/StreamSupervisor-0/flow-0-2-sFtpBrowserSource] Error during postStop in [akka.stream.alpakka.ftp.impl.FtpBrowserGraphStage$$anon$1-sFtpBrowserSource]: Broken transport; encountered EOF
net.schmizz.sshj.connection.ConnectionException: Broken transport; encountered EOF
    at net.schmizz.sshj.connection.ConnectionException$1.chain(ConnectionException.java:32)
    at net.schmizz.sshj.connection.ConnectionException$1.chain(ConnectionException.java:26)
    at net.schmizz.concurrent.Promise.deliverError(Promise.java:95)
    at net.schmizz.concurrent.Event.deliverError(Event.java:74)
    at net.schmizz.concurrent.ErrorDeliveryUtil.alertEvents(ErrorDeliveryUtil.java:34)
    at net.schmizz.sshj.connection.channel.AbstractChannel.notifyError(AbstractChannel.java:239)
    at net.schmizz.sshj.connection.channel.direct.SessionChannel.notifyError(SessionChannel.java:229)
    at net.schmizz.sshj.common.ErrorNotifiable$Util.alertAll(ErrorNotifiable.java:35)
    at net.schmizz.sshj.connection.ConnectionImpl.notifyError(ConnectionImpl.java:261)
    at net.schmizz.sshj.transport.TransportImpl.die(TransportImpl.java:588)
    at net.schmizz.sshj.transport.Reader.run(Reader.java:66)
Caused by: net.schmizz.sshj.transport.TransportException: Broken transport; encountered EOF
    at net.schmizz.sshj.transport.Reader.run(Reader.java:58)

排查与解决方向 #

• 验证连接配置准确性：检查path是否为服务器上存在的有效路径，SftpSettings中的主机地址、端口、认证信息（用户名/密码或密钥）是否正确，确认本地到服务器200.13.144.60:181端口的网络连通性。
• 检查服务器端状态：确认SFTP服务正常运行，当前用户对目标路径有读取权限，服务器未设置过短的连接超时时间，没有主动中断连接的规则。
• 核对依赖版本兼容性：确保Alpakka FTP库与依赖的SSHJ版本匹配，版本冲突可能引发传输层异常。
• 添加超时与重试机制：在SftpSettings中配置合理的连接超时、操作超时参数，为ls操作添加重试逻辑，应对临时连接中断问题。
• 开启详细日志：升级SSHJ日志级别至TRACE，查看连接建立、认证、目录访问的完整流程，定位EOF出现的具体环节。

内容的提问来源于stack exchange，提问作者rEVOLution