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

*** 248,266 ****
      public void exit() {
          Platform.exit();
      }
  }
  ...
  JSObject window = (JSObject) webEngine.executeScript("window");
! window.setMember("app", new JavaApplication());
   * </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>
   * 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>
--- 248,282 ----
      public void exit() {
          Platform.exit();
      }
  }
  ...
+ JavaApplication javaApp = new JavaApplication();
  JSObject window = (JSObject) webEngine.executeScript("window");
! 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>