modules/web/src/main/java/javafx/scene/web/WebEngine.java

@@ -248,19 +248,35 @@
     public void exit() {
         Platform.exit();
     }
 }
 ...
+JavaApplication javaApp = new JavaApplication();
 JSObject window = (JSObject) webEngine.executeScript("window");
-window.setMember("app", new JavaApplication());
+window.setMember("app", javaApp);
  * </code></pre>
  * You can then refer to the object and the method from your HTML page:
  * <pre><code>
 &lt;a href="" onclick="app.exit()"&gt;Click here to exit application&lt;/a&gt;
  * </code></pre>
  * <p>When a user clicks the link the application is closed.
  * <p>
+ * Note that the property value {@code javaApp} of
+ * JavaScript object named {@code app} is implemented as Weak Global Reference.
+ * <pre><code>
+JSObject window = (JSObject) webEngine.executeScript("window");
+window.setMember("app", new JavaApplication());
+ * </code></pre>
+ * <p>
+ * Hence if the property value is a local object {@code "new JavaApplication()"}, the value will be GC'ed in next
+ * GC Cycle.
+ * <pre><code>
+&lt;a href="" onclick="app.exit()"&gt;Click here to exit application&lt;/a&gt;
+ * </code></pre>
+ * <p>
+ * When a user clicks the link, it does not guarantee to execute the callback method {@code exit}.
+ * <p>
  * If there are multiple Java methods with the given name,
  * then the engine selects one matching the number of parameters
  * in the call.  (Varargs are not handled.) An unspecified one is
  * chosen if there are multiple ones with the correct number of parameters.
  * <p>