sftpサーバーでファイルを取得するcronタスクを実装しました。このタスクは2日ごとにのみ機能します。zehonのライブラリを使用してsftp接続を作成し、ファイルを取得しています。先日、このエラーが発生しました：
com.zehon.exception.FileTransferException: org.apache.commons.vfs.FileSystemException: Unknown message with code "Could not determine the type of file "sftp://____:***@ftp.___.org/".".
at com.zehon.FileTransferClient.getFileNamesInFolder(FileTransferClient.java:858)
at com.zehon.sftp.SFTPClient.getFileNamesInFolder(SFTPClient.java:668)
at org.___.si.application.module.imports.ImportService.importer(ImportService.java:66)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:592)
at org.jboss.seam.util.Reflections.invoke(Reflections.java:22)
at org.jboss.seam.intercept.RootInvocationContext.proceed(RootInvocationContext.java:31)
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:56)
at org.jboss.seam.transaction.RollbackInterceptor.aroundInvoke(RollbackInterceptor.java:28)
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
at org.jboss.seam.core.BijectionInterceptor.aroundInvoke(BijectionInterceptor.java:77)
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
at org.jboss.seam.core.MethodContextInterceptor.aroundInvoke(MethodContextInterceptor.java:44)
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
at org.jboss.seam.intercept.RootInterceptor.invoke(RootInterceptor.java:107)
at org.jboss.seam.intercept.JavaBeanInterceptor.interceptInvocation(JavaBeanInterceptor.java:185)
at org.jboss.seam.intercept.JavaBeanInterceptor.invoke(JavaBeanInterceptor.java:103)
at org._____.si.application.module.imports.ImportService_$$_javassist_440.importer(ImportService_$$_javassist_440.java)
at org._____.si.application.module.prestation.demande.tachePeriodique.ImportTache.execute(ImportTache.java:45)
at org.____.si.application.util.batch.GestionnaireDeTache$1$1.process(GestionnaireDeTache.java:104)
at org.jboss.seam.servlet.ContextualHttpServletRequest.run(ContextualHttpServletRequest.java:53)
at org._____.si.application.util.batch.GestionnaireDeTache$1.run(GestionnaireDeTache.java:106)
Caused by: org.apache.commons.vfs.FileSystemException: Unknown message with code "Could not determine the type of file "sftp://_____:***@ftp._____.org/".".
at org.apache.commons.vfs.provider.sftp.SftpFileObject.refresh(SftpFileObject.java:84)
at org.apache.commons.vfs.provider.AbstractFileSystem.resolveFile(AbstractFileSystem.java:366)
at org.apache.commons.vfs.provider.AbstractFileSystem.resolveFile(AbstractFileSystem.java:314)
at org.apache.commons.vfs.provider.AbstractOriginatingFileProvider.findFile(AbstractOriginatingFileProvider.java:86)
at org.apache.commons.vfs.provider.AbstractOriginatingFileProvider.findFile(AbstractOriginatingFileProvider.java:66)
at org.apache.commons.vfs.impl.DefaultFileSystemManager.resolveFile(DefaultFileSystemManager.java:692)
at org.apache.commons.vfs.impl.DefaultFileSystemManager.resolveFile(DefaultFileSystemManager.java:620)
at com.zehon.FileTransferClient.getFileObject(FileTransferClient.java:741)
at com.zehon.FileTransferClient.getFileNamesInFolder(FileTransferClient.java:848)
... 23 more