Use the FileTypeSelector or implement your own FileSelector.
fileObject.findFiles(new FileTypeSelector(FileType.FILE), depthwise, fileList);
This example will only select files and not directories. This might be sufficient for your current problem, but if you want to filter files based on their extension, e.g. ".png", then you must implement your own org.apache.commons.vfs2.FileFilter and use a FileFilterSelector.