Cannot modify read/write permissions from Java on Windows on folders

Question

I am using Apache Commons Virtual File System (VFS).

I am building some unit tests for my code and I need to modify the write permission for a folder, to make it not writeable. I tried the below code:

@Rule
public TemporaryFolder tempFolder = new TemporaryFolder();

@Test
public void test_notWriteable() throws IOException {

    // given
    File dir = tempFolder.newFolder("testDirectory");
    dir.setWritable(false, false);
    when(fileApi.isHdfs()).thenReturn(false);
    when(fileApi.getBaseDirectory()).thenReturn("file://" + dir.getAbsolutePath());

    // when
    String isBaseFolderAccessible = fileApi.isLocalBaseFolderAccessible();

    // then
    assertEquals("dashboard.basedir.not_writeable", isBaseFolderAccessible);
}

The method:

private String isLocalBaseFolderAccessible() {
    try {
        final FileSystemManager fileSystemManager = VFS.getManager();

        final FileObject folder = fileSystemManager.resolveFile(fileApi.getBaseDirectory());
        if (!folder.exists()) {
            return BASEDIR_NOT_FOUND;
        } else if (!folder.isReadable()) {
            return BASEDIR_NOT_READABLE;
        } else if (!folder.isWriteable()) {
            return BASEDIR_NOT_WRITEABLE;
        }
    } catch (Exception exception) {
        final String exceptionMessage = exception.getMessage();
        logger.error("exception while trying to check base directory access: {}", exceptionMessage);
        return SETTINGS_CHECK_BASEDIR_NOT_FOUND_I18N;
    }
    return null;
}

Unfortunately, the method returns null, so the folder is writeable. The problem comes from the fact that isWriteable() is called for AbstractFileObject and it always returns true:

from AbstractFileObject:

protected boolean doIsWriteable() throws Exception

{ return true; }

I also tried using ACLs for changing the permissions, but that also did not work. Does anyone know what I can do to change the folder permissions on Windows, with Java?