Java Plug-In Vs. Java WebStart

[Soma RaviKumar]

Hi,
I have read some stuff about Java Plug-ins and Java WebStart separately but I couldn't understad differences between them. Could someone provide me some specific links which illustrate the following points?

1. When do you use Plug-In and when do you use JWS?

2. What was the actual need for introducing these tools?

[Ilja Preuss]

The Java plugin for browsers is used to run Applets. Applets are embedded into web pages.

Java Webstart starts standalone Java desktop programs over the net. With Webstart, the application doesn't run in a browser - it looks exactly like a normal desktop application, just that the jar files are downloaded from the net.

[Soma RaviKumar]

Thanks a lot Ilja for your reply. Still I have some questions related to this.
During java 1.1 days, I used to run applets in a browser and I didn't see any Java Plug-In at that time.
Why do I need it now?
What are the example situations where I can do that only in the presence of Java Plug-In?
What are the example situations where I don't need Plug-In.

Is this Plug-in a part of JRE? If so, is it an OPTIONAL part or MANDATORY part?
I will appreciate if you could throw some light on this.

Similarly, if you could give me some more examples which illustrate where Java Webstart is needed and where it is not needed, I will be very thankful to you.
Regards,
Soma

[Ilja Preuss]

http://java.sun.com/developer/technicalArticles/JavaLP/javawebstart/index.html should answer most of your questions better than I would be able to...

[Layne Lund]

Originally posted by Soma RaviKumar:
Thanks a lot Ilja for your reply. Still I have some questions related to this.
During java 1.1 days, I used to run applets in a browser and I didn't see any Java Plug-In at that time.
Why do I need it now?

In the days of Java 1.1, the Java Run-time Environment was built in to web browsers such as Internet Explorer and Netscape. This is why you didn't need to install an additional plug-in. All the software needed to run an applet was there as soon as you installed a web browser. However, with the release of Java 1.2, Sun decided to release a separate plug-in. This was probably a good idea since updates to Java don't general coincide with browser updates. This way you can run newer Java code with an older browser.

What are the example situations where I can do that only in the presence of Java Plug-In?
What are the example situations where I don't need Plug-In.

Any applets that are compiled with JDK 1.2 or later require a plug-in. The JRE was no longer built into web browsers after this.

You don't need the plug-in to run desktop applets or enterprise applications such as servlets. However, I would consider servlets at least an intermediate topic, so don't worry about them too much at this point. In either case, you still need the JRE installed. It's just that the browser plug-in is not used in either case.

Is this Plug-in a part of JRE? If so, is it an OPTIONAL part or MANDATORY part?

Yes, the plug-in is part of the JRE and it is "mandatory". In fact, I don't think there are really any "optional" parts of the JRE. But then, I use the default installation procedures. I have never tried to use any advanced customization options that I can remember.

I will appreciate if you could throw some light on this.

Layne

[Soma RaviKumar]

Thank you very much Layne for your very clear explanation.
If your time permits, could you please throw some light on JavaWebstart also in this way. Of course, I read the above link on JavaWebstart, but it is more technical. I want something as simple an explanation as you did for the Plug-in.
Thanks in advance,
Soma

[Layne Lund]

I'm sorry, but I'm not very knowledgable about Java WebStart. In fact, I have never used it in my programming. Most of my Java development is for desktop applications that I use on my own system. I haven't had to worry about deployment issues that would prompt me to look into JWS. In fact, that's really all I know about it: JWS is a technology that allows you to distribute a desktop Java app so other people can use it.

Sorry that I cannot be any more help here.

Layne
[ January 10, 2006: Message edited by: Layne Lund ]