javafx Update message from walkfiletree method of Filevisitor

Question

I am using java 7 Files.walkFileTree method to traverse through whole disk. I am trying to update the javafx label and progress bar in the UI class I have created, from the visitFile() method of my custom FileVisitor. In the javafx UI class I create the task and start it. I did some research and someone suggested I implement FileVisitor and extend task so that I can updateMessage() from visitFile() but I tried that and it does not work. Javafx UI class :

          FileSystemTraverse task = new FileSystemTraverse(client);
          // here i create label and bind it to the task
          final Thread thread = new Thread(task);
          thread.start();

FileSystemTraverse class :

          public class FileSystemTraverse extends Task implements FileVisitor<Path>
          {
          // The usual implemented methods, constructor and so on ... 

            public FileVisitResult visitFile(Path filePath, BasicFileAttributes attributes) throws IOException {
              Objects.requireNonNull(attributes);
              Objects.requireNonNull(filePath);
              if (attributes.isRegularFile()) {
                // Here I do some operations and if I found the file i need
                // I update the message (this is just an example) 
                updateMessage(filePath.toString);
              }
              return FileVisitResult.CONTINUE;
            }

            @Override
            protected Object call() throws Exception {
              Path path = Paths.get("D:\\");
              // This one below  gets updated in the UI.
              updateMessage("asdkjasdkjhakj");
              FileSystemTraverse printFiles = new FileSystemTraverse(client);
              Files.walkFileTree(path,printFiles);
              return null;
            }

          }

So my question is - is there really a way of doing this ? I read somewhere here about doing this with swing (they use publish) but with javafx it does not seem to work.

Thank you in advance.