apache VFS2 uriStyle - root absolute path ends with double slash - ftp

Question

while working on an ftp server with the vfs2 library I noticed, that I had to enable VFS.setUriStyle(true) so the library would change the working directory to parent directory of the target file I am operating on (cwd directoryName).
But if UriStyle is enabled, everything is being resolved relativly to the root. Which would not be a Problem if the root was not "//".
The class GenericFileName sets the absolutePath of the root to "/", which makes the Method getPath() return "/"+getUriTrailer() which in the case of the root always returns "//". Everything that is resolved relativly to // has two dots proceeding to their path.
Which means if I execute the following code:
public class RemoteFileTest {
public static void main(String[] args) {
// Options for a RemoteFileObject connection
VFS.setUriStyle(true);
FileSystemOptions options = new FileSystemOptions();
// we doing an ftp connection, hence we use the ftpConfigBuilder
// we want to work in passive mode
FtpFileSystemConfigBuilder.getInstance().setPassiveMode(options, true);
FtpFileSystemConfigBuilder.getInstance().setUserDirIsRoot(options, false);
// DefaultFileSystemConfigBuilder.getInstance().setRootURI(options, "/newRoot/");
// System.out.println(DefaultFileSystemConfigBuilder.getInstance().getRootURI(options));
// ftp://localhost:21/
StaticUserAuthenticator auth = new StaticUserAuthenticator("", "user", "pass");
try {
DefaultFileSystemConfigBuilder.getInstance().setUserAuthenticator(options, auth);
} catch (FileSystemException e) {
e.printStackTrace();
return;
}
// A FileSystemManager creates an abstract FileObject linked to are desired RemoteFile.
// That link is just simulated and not yet real.
FileSystemManager manager;
try {
manager = VFS.getManager();
} catch (FileSystemException e) {
e.printStackTrace();
return;
}
try (FileObject remoteFile = manager.resolveFile("ftp://localhost:21/sub_folder/test.txt", options)) {
System.out.println("Is Folder " + remoteFile.isFolder());
System.out.println("Is File " + remoteFile.isFile());
} catch (FileSystemException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return;
}
}}
I receive this interaction with the ftp server:
USER user
PASS ****
TYPE I
CWD //
SYST
PASV
LIST ..sub_folder/
PWD
CWD ..sub_folder/
I want the interaction to be just like this, but without the two dots infront of the directory.
Kind regards
Barry

Answer 1

Fixed it as described below:
Disabled uriStyle again.
Wrote my own VFS class which creates my custom written Manager.
That Manager overwrites the FtpFileProvider with my custom one, which simply sets the root to a custom selected one, which causes the desired behaviour.
import org.apache.commons.vfs2.FileName;
import org.apache.commons.vfs2.FileObject;
import org.apache.commons.vfs2.FileSystem;
import org.apache.commons.vfs2.FileSystemException;
import org.apache.commons.vfs2.FileSystemOptions;
import org.apache.commons.vfs2.impl.DefaultFileSystemConfigBuilder;
import org.apache.commons.vfs2.provider.ftp.FtpFileProvider;
public class AdvancedFtpFileProvider extends FtpFileProvider {
public AdvancedFtpFileProvider() {
super();
// setFileNameParser(AdvancedFtpFileNameParser.getInstance());
}
#Override
protected FileObject findFile(FileName name, FileSystemOptions fileSystemOptions) throws FileSystemException {
// Check in the cache for the file system
//getContext().getFileSystemManager().resolveName... resolves the configured RootUri relative to the selected root (name.getRoot()). This calls cwd to the selectedRoot and operates from there with relatives urls towards the new root!
final FileName rootName = getContext().getFileSystemManager().resolveName(name.getRoot(), DefaultFileSystemConfigBuilder.getInstance().getRootURI(fileSystemOptions));
final FileSystem fs = getFileSystem(rootName, fileSystemOptions);
// Locate the file
// return fs.resolveFile(name.getPath());
return fs.resolveFile(name);
}
}

Answer 2

Came across this question because I was having the same issue with the following
ftp://user:pass#host//home/user/file.txt
becoming... (note the single slash after 'home')
ftp://user:pass#host/home/user/file.txt
I did this to solve the issue...
// Setup some options, add as many as you need
FileSystemOptions opts = new FileSystemOptions( );
// This line tells VFS to treat the URI as the absolute path and not relative
FtpsFileSystemConfigBuilder.getInstance( ).setUserDirIsRoot( opts, false );
// Retrieve the file from the remote FTP server
FileObject realFileObject = fileSystemManager.resolveFile( fileSystemUri, opts );
I hope this can help someone, if not then provide a reference for the next time this stumps me.