8256362: JavaFX must warn when the javafx.* modules are loaded from the classpath

Reviewed-by: arapte, pbansal, jvos

Author: kevinrushforth

modules/javafx.graphics/src/main/java/com/sun/javafx/application/PlatformImpl.java

@@ -31,8 +31,10 @@
 import com.sun.javafx.tk.TKListener;
 import com.sun.javafx.tk.TKStage;
 import com.sun.javafx.tk.Toolkit;
+import com.sun.javafx.util.Logging;
 import com.sun.javafx.util.ModuleHelper;
 
+import java.lang.module.ModuleDescriptor;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.security.AccessControlContext;
@@ -187,6 +189,23 @@ public static void startup(final Runnable r, boolean preventDuplicateCalls) {
             return;
         }
 
+        final Module module = PlatformImpl.class.getModule();
+        final ModuleDescriptor moduleDesc = module.getDescriptor();
+        if (!module.isNamed()
+                || !"javafx.graphics".equals(module.getName())
+                || moduleDesc == null
+                || moduleDesc.isAutomatic()
+                || moduleDesc.isOpen()) {
+
+            String warningStr = "Unsupported JavaFX configuration: "
+                + "classes were loaded from '" + module + "'";
+            if (moduleDesc != null) {
+                warningStr += ", isAutomatic: " + moduleDesc.isAutomatic();
+                warningStr += ", isOpen: " + moduleDesc.isOpen();
+            }
+            Logging.getJavaFXLogger().warning(warningStr);
+        }
+
         AccessController.doPrivileged((PrivilegedAction<Void>) () -> {
             applicationType = System.getProperty("com.sun.javafx.application.type");
             if (applicationType == null) applicationType = "";

modules/javafx.graphics/src/main/java/javafx/application/Application.java

@@ -80,6 +80,12 @@
  * {@link #stop} method returns or {@link System#exit} is called.
  * </p>
  *
+ * <p><b>Note:</b> The JavaFX classes must be loaded from a set of
+ * named {@code javafx.*} modules on the <em>module path</em>.
+ * Loading the JavaFX classes from the classpath is not supported.
+ * See {@link Platform#startup(Runnable) Platform.startup}
+ * for more information.
+ *
  * <p><b>Deploying an Application as a Module</b></p>
  * <p>
  * If the {@code Application} subclass is in a named module then that class

modules/javafx.graphics/src/main/java/javafx/application/Platform.java

@@ -90,6 +90,14 @@ private Platform() {
      * that the JavaFX runtime be started once.
      * </p>
      *
+     * <p><b>Note:</b> The JavaFX classes must be loaded from a set of
+     * named {@code javafx.*} modules on the <em>module path</em>.
+     * Loading the JavaFX classes from the classpath is not supported.
+     * A warning is logged when the JavaFX runtime is started if the JavaFX
+     * classes are not loaded from the expected named module.
+     * This warning is logged regardless of whether the JavaFX runtime was
+     * started by calling this method or automatically as described above.
+     *
      * @throws IllegalStateException if the JavaFX runtime is already running
      *
      * @param runnable the Runnable whose run method will be executed on the

modules/javafx.graphics/src/main/java/module-info.java

@@ -30,6 +30,12 @@
  * as well as APIs for animation, css, concurrency, geometry, printing, and
  * windowing.
  *
+ * <p><b>Note:</b> The JavaFX classes must be loaded from a set of
+ * named {@code javafx.*} modules on the <em>module path</em>.
+ * Loading the JavaFX classes from the classpath is not supported.
+ * See {@link javafx.application.Platform#startup(Runnable) Platform.startup}
+ * for more information.
+ *
  * @moduleGraph
  * @since 9
  */