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https://issues.apache.org/jira/browse/VFS-437?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13459111#comment-13459111
]
Jason commented on VFS-437:
---------------------------
On the remote ftp server (I used CentOs distribution)
1. Create a Voll directory under file system so the path is "/Vol"
2. Create a Vol1 directory under the user's home directory so the path is
"/user/Vol1"
3. Make the Vol1 under step two soft link to the Vol1 in step one, so "ls -al"
would show the following
"lrwxrwxrwx 1 root root 5 Oct 5 2007 Vol1 -> /Vol1"
I used the test case you've written, I can actually reproduce the exception
also. The only difference is my ftp server is not a localhost.
@Test
public void test() throws FileSystemException
{
FileSystemOptions opts = new FileSystemOptions();
FtpFileSystemConfigBuilder.getInstance().setUserDirIsRoot(opts, true);
final FileObject file =
VFS.getManager().resolveFile("ftp://test1:test1@remoteIp/Vol1", opts);
System.out.println(file);
for (FileObject child : file.getChildren())
{
System.out.println(child);
for (FileObject child2 : child.getChildren())
{
System.out.println(child2);
}
}
}
I reproduce this issue with scenario of Windows 7 and Linux(Centos) trying to
access a Linux ftp remote server.
> [FTP] Program crashes when StackOverFlow Exception happens from pulling a
> softlinked directory that link to the directory that has the same name one
> level above
> -----------------------------------------------------------------------------------------------------------------------------------------------------------------
>
> Key: VFS-437
> URL: https://issues.apache.org/jira/browse/VFS-437
> Project: Commons VFS
> Issue Type: Bug
> Affects Versions: 2.0
> Environment: java version "1.7.0_02"
> Java(TM) SE Runtime Environment (build 1.7.0_02-b13)
> Java HotSpot(TM) 64-Bit Server VM (build 22.0-b10, mixed mode)
> Linux version 2.6.18-238.el5 ([email protected]) (gcc version
> 4.1.2 20080704 (Red Hat 4.1.2-48)) #1 SMP Thu Jan 13 15:51:15 EST 2011
> Reporter: Jason
> Priority: Blocker
> Fix For: 2.1
>
>
> With the setting below, StackOverFlow exceptions occur and server crashes
> set the builder.setUserDirlsRoot (opt, true)
> Attept to pull with:
> ftp://root:password@ip:/Vol1
> Vol directory has the following info
> lrwxrwxrwx 1 root root 5 Oct 5 2007 Vol1 -> /Vol1
> When it tries to look for the parent of the Vol1, it goes back to the same
> Vol1, which causes a infinite loop that eventually creates stackoverflow
> exception.
> The problem is inside the doGetType() method in FtpFileObject
> @Override
> protected FileType doGetType()
> throws Exception
> {
> // VFS-210
> synchronized (getFileSystem())
> {
> if (this.fileInfo == null)
> {
> getInfo(false);
> }
> if (this.fileInfo == UNKNOWN)
> {
> return FileType.IMAGINARY;
> }
> else if (this.fileInfo.isDirectory())
> {
> return FileType.FOLDER;
> }
> else if (this.fileInfo.isFile())
> {
> return FileType.FILE;
> }
> else if (this.fileInfo.isSymbolicLink())
> {
> return getLinkDestination().getType();
> }
> }
> throw new FileSystemException("vfs.provider.ftp/get-type.error",
> getName());
> }
> It will keep hitting the "else if (this.fileinfo.isSymbolicLink())" condition
> and the fileinfo displayed is always the Vol1 under root directory.
> Exception is shown below
> java.lang.StackOverflowError
> at org.apache.commons.net.ftp.FTPFile.isDirectory(FTPFile.java:116)
> at
> org.apache.commons.vfs2.provider.ftp.FtpFileObject.doGetType(FtpFileObject.java:334)
> at
> org.apache.commons.vfs2.provider.AbstractFileObject.getType(AbstractFileObject.java:496)
> at
> org.apache.commons.vfs2.provider.ftp.FtpFileObject.doGetType(FtpFileObject.java:344)
> at
> org.apache.commons.vfs2.provider.AbstractFileObject.getType(AbstractFileObject.java:496)
> at
> org.apache.commons.vfs2.provider.ftp.FtpFileObject.doGetType(FtpFileObject.java:344)
> at
> org.apache.commons.vfs2.provider.AbstractFileObject.getType(AbstractFileObject.java:496)
> at
> org.apache.commons.vfs2.provider.ftp.FtpFileObject.doGetType(FtpFileObject.java:344)
> at
> org.apache.commons.vfs2.provider.AbstractFileObject.getType(AbstractFileObject.java:496)
> at
> org.apache.commons.vfs2.provider.ftp.FtpFileObject.doGetType(FtpFileObject.java:344)
> at
> org.apache.commons.vfs2.provider.AbstractFileObject.getType(AbstractFileObject.java:496)
> at
> org.apache.commons.vfs2.provider.ftp.FtpFileObject.doGetType(FtpFileObject.java:344)
> at
> org.apache.commons.vfs2.provider.AbstractFileObject.getType(AbstractFileObject.java:496)
> at
> org.apache.commons.vfs2.provider.ftp.FtpFileObject.doGetType(FtpFileObject.java:344)
> at
> org.apache.commons.vfs2.provider.AbstractFileObject.getType(AbstractFileObject.java:496)
> at
> org.apache.commons.vfs2.provider.ftp.FtpFileObject.doGetType(FtpFileObject.java:344)
> at
> org.apache.commons.vfs2.provider.AbstractFileObject.getType(AbstractFileObject.java:496)
> at
> org.apache.commons.vfs2.provider.ftp.FtpFileObject.doGetType(FtpFileObject.java:344)
> at
> org.apache.commons.vfs2.provider.AbstractFileObject.getType(AbstractFileObject.java:496)
> at
> org.apache.commons.vfs2.provider.ftp.FtpFileObject.doGetType(FtpFileObject.java:344)
> at
> org.apache.commons.vfs2.provider.AbstractFileObject.getType(AbstractFileObject.java:496)
> at
> org.apache.commons.vfs2.provider.ftp.FtpFileObject.doGetType(FtpFileObject.java:344)
> at
> org.apache.commons.vfs2.provider.AbstractFileObject.getType(AbstractFileObject.java:496)
> at
> org.apache.commons.vfs2.provider.ftp.FtpFileObject.doGetType(FtpFileObject.java:344)
> at
> org.apache.commons.vfs2.provider.AbstractFileObject.getType(AbstractFileObject.java:496)
> at
> org.apache.commons.vfs2.provider.ftp.FtpFileObject.doGetType(FtpFileObject.java:344)
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