Java. How to set value in JavaFX progress-bar from another class?

Question

Java

Good evening. I wrote a small program in which there are only 3 classes.
Main launching a JavaFX window via an fxml file.
ActionsMain Handles the events of all controls on the form.
Archivations takes the directory to be archived and sends it to the archive via a ZipOutputStream recursively traversing the walkFileTree directory.
In the same Archivations class, the process of calculating the progress of execution takes place. And it should inform the class that called ActionsMain that its progress has changed. And ActionsMain, in turn, should change the value on the progress bar. Everything would be fine, but only Exeptions arise
And here is the hero of the occasion:

/usr/lib/jvm/jdk1.8.0_77/bin/java -Didea.launcher.port=7535 -Didea.launcher.bin.path=/home/grabedinex/Загрузки/IDEA/idea/idea-IU-145.597.3/bin -Dfile.encoding=UTF-8 -classpath /usr/lib/jvm/jdk1.8.0_77/jre/lib/charsets.jar:/usr/lib/jvm/jdk1.8.0_77/jre/lib/deploy.jar:/usr/lib/jvm/jdk1.8.0_77/jre/lib/ext/cldrdata.jar:/usr/lib/jvm/jdk1.8.0_77/jre/lib/ext/dnsns.jar:/usr/lib/jvm/jdk1.8.0_77/jre/lib/ext/jaccess.jar:/usr/lib/jvm/jdk1.8.0_77/jre/lib/ext/jfxrt.jar:/usr/lib/jvm/jdk1.8.0_77/jre/lib/ext/localedata.jar:/usr/lib/jvm/jdk1.8.0_77/jre/lib/ext/nashorn.jar:/usr/lib/jvm/jdk1.8.0_77/jre/lib/ext/sunec.jar:/usr/lib/jvm/jdk1.8.0_77/jre/lib/ext/sunjce_provider.jar:/usr/lib/jvm/jdk1.8.0_77/jre/lib/ext/sunpkcs11.jar:/usr/lib/jvm/jdk1.8.0_77/jre/lib/ext/zipfs.jar:/usr/lib/jvm/jdk1.8.0_77/jre/lib/javaws.jar:/usr/lib/jvm/jdk1.8.0_77/jre/lib/jce.jar:/usr/lib/jvm/jdk1.8.0_77/jre/lib/jfr.jar:/usr/lib/jvm/jdk1.8.0_77/jre/lib/jfxswt.jar:/usr/lib/jvm/jdk1.8.0_77/jre/lib/jsse.jar:/usr/lib/jvm/jdk1.8.0_77/jre/lib/management-agent.jar:/usr/lib/jvm/jdk1.8.0_77/jre/lib/plugin.jar:/usr/lib/jvm/jdk1.8.0_77/jre/lib/resources.jar:/usr/lib/jvm/jdk1.8.0_77/jre/lib/rt.jar:/home/grabedinex/Project/Lineage/Laucnehr/Launcher_archivator/out/production/Launcher_archivator:/home/grabedinex/Загрузки/IDEA/idea/idea-IU-145.597.3/lib/idea_rt.jar com.intellij.rt.execution.application.AppMain com.grabedinex.launcher.main.Main
0.5
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
  at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1774)
  at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1657)
  at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
  at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
  at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
  at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
  at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
  at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
  at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
  at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
  at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
  at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
  at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
  at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
  at javafx.event.Event.fireEvent(Event.java:198)
  at javafx.scene.Node.fireEvent(Node.java:8411)
  at javafx.scene.control.Button.fire(Button.java:185)
  at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:182)
  at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:96)
  at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89)
  at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
  at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
  at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
  at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
  at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
  at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
  at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
  at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
  at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
  at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
  at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
  at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
  at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
  at javafx.event.Event.fireEvent(Event.java:198)
  at javafx.scene.Scene$MouseHandler.process(Scene.java:3757)
  at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485)
  at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
  at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
  at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:352)
  at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:275)
  at java.security.AccessController.doPrivileged(Native Method)
  at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$354(GlassViewEventHandler.java:388)
  at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
  at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:387)
  at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
  at com.sun.glass.ui.View.notifyMouse(View.java:937)
  at com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
  at com.sun.glass.ui.gtk.GtkApplication.lambda$null$49(GtkApplication.java:139)
  at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.reflect.InvocationTargetException
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  at java.lang.reflect.Method.invoke(Method.java:498)
  at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
  at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  at java.lang.reflect.Method.invoke(Method.java:498)
  at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
  at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1769)
  ... 48 more
Caused by: java.lang.NullPointerException
  at com.grabedinex.launcher.main.ActionsMain.Upp(ActionsMain.java:92)
  at com.grabedinex.launcher.main.ActionsMain.UpdateProgress(ActionsMain.java:88)
  at com.grabedinex.launcher.archivations.Arcivations.Progressbar_change(Arcivations.java:50)
  at com.grabedinex.launcher.archivations.Arcivations$1.visitFile(Arcivations.java:94)
  at com.grabedinex.launcher.archivations.Arcivations$1.visitFile(Arcivations.java:80)
  at java.nio.file.Files.walkFileTree(Files.java:2670)
  at java.nio.file.Files.walkFileTree(Files.java:2742)
  at com.grabedinex.launcher.archivations.Arcivations.AddDirectoryRecursive(Arcivations.java:80)
  at com.grabedinex.launcher.archivations.Arcivations.archivate(Arcivations.java:74)
  at com.grabedinex.launcher.main.ActionsMain.PackDirectory(ActionsMain.java:71)
  at com.grabedinex.launcher.main.ActionsMain.btnStartPatch_action(ActionsMain.java:57)
  ... 58 more

Process finished with exit code 0

In order not to clog the topic, and the whole code will not fit, I will indicate links to the pastebin of all classes.
Main: pastebin.com/2gfDiC3G
FXML to it: pastebin.com/ggsMQcmc
ActionsMain(Handling form events): pastebin.com/nAeW5ffN
Archivations(My archiving class): pastebin.com/buymrD2c

Answer 1

For workpiece

@Override
    public void propertyChange(PropertyChangeEvent evt) {
        System.out.println("Property \"" + evt.getPropertyName() + "\" has new value: " + evt.getNewValue());
    }

Pay no attention. This is my attempt to implement a listener. Unfortunately without success.
Now everything is called from Archivations.Progressbar_change()
Namely actionsMain.UpdateProgress(this.progressbar_change);
It seems to have decided. Passed to the archiving class a reference to the ProgressBar object, which is loaded from XML. Works. In general, how can such questions be implemented more correctly?