8248122: java launcher should launch normally if JavaFX modules not found

Reviewed-by: kcr, prr, aivanov

Author: Christopher Schnick

src/java.base/share/classes/sun/launcher/LauncherHelper.java

@@ -98,6 +98,8 @@ private LauncherHelper() {}
             "javafx.application.Application";
     private static final String JAVAFX_FXHELPER_CLASS_NAME_SUFFIX =
             "sun.launcher.LauncherHelper$FXHelper";
+    private static final String JAVAFX_GRAPHICS_MODULE_NAME =
+            "javafx.graphics";
     private static final String LAUNCHER_AGENT_CLASS = "Launcher-Agent-Class";
     private static final String MAIN_CLASS = "Main-Class";
     private static final String ADD_EXPORTS = "Add-Exports";
@@ -768,8 +770,9 @@ public static Class<?> checkAndLoadMain(boolean printToStderr,
          * the main class may or may not have a main method, so do this before
          * validating the main class.
          */
-        if (JAVAFX_FXHELPER_CLASS_NAME_SUFFIX.equals(mainClass.getName()) ||
-            doesExtendFXApplication(mainClass)) {
+        if ((JAVAFX_FXHELPER_CLASS_NAME_SUFFIX.equals(mainClass.getName()) ||
+                doesExtendFXApplication(mainClass)) &&
+                ModuleLayer.boot().findModule(JAVAFX_GRAPHICS_MODULE_NAME).isPresent()) {
             // Will abort() if there are problems with FX runtime
             FXHelper.setFXLaunchParameters(what, mode);
             mainClass = FXHelper.class;
@@ -1082,9 +1085,6 @@ public String toString() {
 
     static final class FXHelper {
 
-        private static final String JAVAFX_GRAPHICS_MODULE_NAME =
-                "javafx.graphics";
-
         private static final String JAVAFX_LAUNCHER_CLASS_NAME =
                 "com.sun.javafx.application.LauncherImpl";