• JavaFx Scene Graph is not thread Safe.
    • JavaFX application,  also known as the JavaFX Application thread, is not thread safe.
    • Implementing long-running tasks on the JavaFX Application thread may pose  UI unresponsive risks.
    •  A best practice is to do these tasks on one or more background threads and let the JavaFX Application thread process user events.
      If you have special requirements or need extra power over the code, implementing a background worker by creating a Runnable object and a new thread is an appropriate way to go. Note that at some point you must communicate with the JavaFX Application thread, either with a result or with the progress of the background task.
  • For the most cases and for the majority of developers the recommended way is to use the JavaFX APIs provided by the javafx.concurrent package, which takes care of multithreaded code that interacts with the UI and ensures that this interaction happens on the correct thread.