apache VFS2 uriStyle - root absolute path ends with double slash

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.