Thread: Stop applet from running

Greetings

I have created an web application (jsp-servlet) that trigers some .jar applets
I print the jars with the HTML tags through a servlet in the jsp.

Imagine two situations. A anb B.
Starting with A the jar runs.
I go to B, the 2nd jar replaces the first.
When I return back to A, the 2nd jar is removed but the first jar fails to start with a Adding same VBO twice + null pointer exception.

So I believe I have to stop it after leaving situation A.
Is there a way to stop the .jar from running from inside the servlet?

Added stacktrace:

Adding same VBO twice. Exception in thread "Animation Thread" P3D: Already called beginDraw(). javax.media.opengl.GLException: java.lang.NullPointerException at jogamp.opengl.awt.AWTThreadingPlugin.invokeOnOpenG LThread(AWTThreadingPlugin.jav*​a:98) at jogamp.opengl.ThreadingImpl.invokeOnOpenGLThread(T hreadingImpl.java:196) at javax.media.opengl.Threading.invokeOnOpenGLThread( Threading.java:164) at javax.media.opengl.awt.GLCanvas.maybeDoSingleThrea dedWorkaround(GLCanvas.java:83*​1)

The browser loads the jsp page from apache server at a URL (localhost).
The user presses a button.
The browser sends a request to the server to execute a servlet.
The servlet prints on the jsp the first applet (A.jar) in a div to the browser.
The user presses a button (type + search - change values).
The browser sends a request to the server to execute a servlet.
The servlet prints on the jsp the second applet (B.jar) in the same div to the browser, replacing the first.

I believe there is the problem. I have to stop the applet right after the next request is made.

I am using jQuery to handle the processRequest, so I do not replace the hole page, and I print the result of that (from the servlet) in a HTML <div> tag.

The A.jar is called from a <script> tag as an <object> tag. Stored in a var called objectElement.

How can I call the methods from an applet that is called like that?

Could you tell me for example, the methods from java would be called like this?

A.stop(); and A.destroy();

Thank you for your time.