About Applets

[418928]

Hi everybody,

The following things are not clear to me. I have searched several
documents and do some experiments myself, but I'd like to check some
things. I'm also worried about the compatibility of the answers
regarding different web browsers.

1) What happens if there are two applets with the same id/name on the
same or on a different web page? Does this allow to re-use the old
applet?

2) When is a new JVM process launched by a browser? For example, if I
connect to a certain URL that has a browser, it is clear that a Java
process will start to process the applet. But what happens if now I
launch another browser window that also declares an applet? Is the JVM
previously launched shared for the new applet? Or a new JVM is
launched? And if I execute a new instance of the browser?

3) Related to the previous question, if the JVM is not shared, is
there any way to detect if a certain applet is running on any JVM and
obtain a reference to it (using Javascript)?

4) What should happen if I connect twice to the same URL with the same
applet declared? Are two instances of the same applet executed or can
I "see" the old applet running?

5) Is the communication way of communicating with an applet from
Javascript standard? I know that JSObject (Applet->javascript) is not
compatible with some browsers, but I have not found any document
indicating that the javascript->applet could fail with some browsers.

Thanks,
Sergio.

 

[Andrew Thompson]

Hi everybody,

The following things are not clear to me. I have searched several
documents and do some experiments myself, but I'd like to check some
things. I'm also worried about the compatibility of the answers
regarding different web browsers.

You have good cause for worry.

1) What happens if there are two applets with the same id/name on the
same or on a different web page? Does this allow to re-use the old
applet?

No. Not in any reliable way.
It would be against the HTML recommendations
to have two elements with identical ID's, so
a browser would be free to render such
elements any way it likes, some browser
might put the applet in both ID's.

2) When is a new JVM process launched by a browser?

It depends on the browser (as well as OS,
and sometimes version of browser).

If you want something reliable, avoid
browsers altogether.

What benefit are you aiming to supply
to the end user?

Andrew T.