Re: Java Applets to JSP Conversion

From:
Lew <lew@lewscanon.com>
Newsgroups:
comp.lang.java.programmer
Date:
Thu, 01 Nov 2007 20:17:42 -0400
Message-ID:
<C6WdnU7vOpc78bfanZ2dnUVZ_qWtnZ2d@comcast.com>
The One wrote:

I am looking for a project to convert the existing JAVA


Andrew Thompson wrote:

It is 'Java', not 'JAVA'.

....

You're looking at a rewrite, not a conversion. The lifecycle and user
interaction models of applets and serlvet/JSP systems are not
fundamentally compatible with each other.

If the applet is relatively well-designed you'll be able to salvage
the core "business logic" part of the applet, but you won't be able to
reuse much, if any, of the UI code.

That said, it's odd that you've found that parts of an applet written
for 1.3 do not work under newer Java versions (1.5, 1.6). Can you
elaborate a bit on that?


The One wrote:

I thought there might be some work around for this conversion. Let me
know if anybody has some sort of tutorial or process that can explain
the process a bit. Certainly it depends on current implementation but
still some generic version of the process would be a good way to
start.


There is none that I've encountered. You will note that Andrew pointed out that:

The lifecycle and user interaction models of applets and serlvet/JSP systems are not
fundamentally compatible with each other.


They are fundamentally different. Applets run in a JVM in the browser.
Servlets run in an application server on a server.

I don't think it's meaningful to speak of a "conversion" from applets to
servlets. They're as different as apples and oranges.

As Andrew pointed out:

You're looking at a rewrite, not a conversion.


The One wrote:

Frankly, the application is very old and java [sic] client shows error on


It's "Java".

some parts of the system on newer JAVA [sic] versions. Also, sometimes when


It's "Java".

user want to use this application they need to get a computer with
JAVA [sic] client installed.. I wish I have to just work on the part that is
not working on higher JAVA [sic] versions.. but unfortunately that's not the
case..


You have been asked before. What part doesn't work on newer Java (not "JAVA")
versions?

Thanks for the help.


We could help more if you answered our questions.

Let's summarize:
- Going from applet to servlet is not a "conversion", it's a rewrite.
- Applets run just in a JVM, within a browser. Servlets run in an application
server.
- The language is spelled "Java". It's a proper noun.
- Java Web Start will likely solve the problems with your applets. It is a
conversion from applet to application and much less difficult than rewriting
as a servlet.
- What "part ... is not working on higher [Java] versions"?

--
Lew

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