Check if file exists using Apache Commons VFS2

Question

I would like to ask if there is a way how to check if file already exists in the folder using only Apache Commons.

I have method which uploads into the SFTP folder but it overwrites current files anytime the method is running. The method is set to run every 5 minutes. I need a code which will create and if statement which checks if the file is not at the SFTP location already and then, if not executes my copy method, if there is a file, then skips it.

My copy method looks like this

private void copyFileSFTP(File model, String hour) throws IOException {
    StandardFileSystemManager manager = new StandardFileSystemManager();
    String dest = String.format("%s/%s/model/%s", destinationPath, hour,
            model.getName());

    remoteDirectory = String.format("%s/%s/model/", destinationPath, hour);

    try {
        if (!model.exists())
            LOG.error("Error. Local file not found");

        // Initializes the file manager
        manager.init();

        // Setup our SFTP configuration
        FileSystemOptions opts = new FileSystemOptions();
        SftpFileSystemConfigBuilder.getInstance().setStrictHostKeyChecking(
                opts, "no");
        SftpFileSystemConfigBuilder.getInstance().setUserDirIsRoot(opts,
                false);
        SftpFileSystemConfigBuilder.getInstance().setTimeout(opts, 10000);

        // Create the SFTP URI using the host name, userid, password, remote
        // path and file name
        String sftpUri = "sftp://" + userId + ":" + password + "@"
                + serverAddress + "/" + remoteDirectory + model.getName();
        
        **HERE I NEED THE CHECK IF THE MODEL EXISTS ALREADY ON SFTP**

        // Create local file object
        FileObject localFile = manager.resolveFile(model.getAbsolutePath());

        // Create remote file object
        FileObject remoteFile = manager.resolveFile(sftpUri, opts);

        // Copy local file to sftp server
        remoteFile.copyFrom(localFile, Selectors.SELECT_SELF);
        LOG.info("File upload successful");
        LOG.info("New file has been created.");
        LOG.info(dest);

    } catch (Exception ex) {
        LOG.error(ex);
        handleBadPath(model, hour);

    } finally {
        manager.close();
    }

}

I have checked SFTP Upload Download Exist and Move using Apache Commons VFS – and this looks like the file is firstly created and then checked for (number 2) - not checked and then created.

Thank you for help.

Answer 1

Use FileObject.exists() method.

See https://commons.apache.org/proper/commons-vfs/commons-vfs2/apidocs/org/apache/commons/vfs2/FileObject.html#exists()

... as called in the code you have linked in your question, except they do not use the return value of .exists() at all. And they use the check probably to verify that upload succeeded, not to prevent an overwrite.