src/java.desktop/windows/classes/sun/awt/windows/WToolkit.java

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 1996, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1996, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this

@@ -45,10 +45,11 @@
 import sun.awt.AWTAccessor;
 import sun.awt.AppContext;
 import sun.awt.AWTAutoShutdown;
 import sun.awt.AWTPermissions;
 import sun.awt.AppContext;
+import sun.awt.DisplayChangedListener;
 import sun.awt.LightweightFrame;
 import sun.awt.SunToolkit;
 import sun.awt.util.ThreadGroupUtils;
 import sun.awt.Win32GraphicsDevice;
 import sun.awt.Win32GraphicsEnvironment;

@@ -800,13 +801,14 @@
 
     @Override
     public native int getMaximumCursorColors();
 
     static void paletteChanged() {
-        ((Win32GraphicsEnvironment)GraphicsEnvironment
-        .getLocalGraphicsEnvironment())
-        .paletteChanged();
+        Object lge = GraphicsEnvironment.getLocalGraphicsEnvironment();
+        if (lge instanceof DisplayChangedListener) {
+            ((DisplayChangedListener) lge).paletteChanged();
+        }
     }
 
     /*
      * Called from Toolkit native code when a WM_DISPLAYCHANGE occurs.
      * Have Win32GraphicsEnvironment execute the display change code on the

@@ -814,13 +816,14 @@
      */
     public static void displayChanged() {
         EventQueue.invokeLater(new Runnable() {
             @Override
             public void run() {
-                ((Win32GraphicsEnvironment)GraphicsEnvironment
-                .getLocalGraphicsEnvironment())
-                .displayChanged();
+                Object lge = GraphicsEnvironment.getLocalGraphicsEnvironment();
+                if (lge instanceof DisplayChangedListener) {
+                    ((DisplayChangedListener) lge).displayChanged();
+                }
             }
         });
     }
 
     /**