🚀 go-pugleaf

What's the use ?


jan


"BH" <bohiggy@yahoo.com> schrieb im Newsbeitrag
news:3dcbe4ef$1@newsgroups.borland.com...
> Hello coders:
>
> Surely this has been asked before, but I can't find a clear answer yet.
> We're new to java and wondering about the prospects of easing it into our
> current non-java apps until they are eventually 100% java....
>
> Is it possible to "blend" java desktop or C/S app widgets (not web/browser
> stuff) with a win32 app such that the java portions appear to be part of
the
> calling win32 app or dll?  Asked another way, can an app built with
> Dephi/C++Builder/whatever use some java pieces ( objects, windows, data
> input
> screens, etc ) that appear to be part of the same "parent" win32
application
> from the user's point of view?
>
> If the answer is yes, any thoughts/links/resources would be appreciated...
>
> BH
>
>
>
>
>

BH wrote:

> We're new to java and wondering about the prospects of easing it into 
> our current non-java apps until they are eventually 100% java....
>
> Is it possible to "blend" java desktop or C/S app widgets (not 
> web/browser stuff) with a win32 app such that the java portions appear 
> to be part of the calling win32 app or dll?  

Not without some difficulty, but it's not impossible.

The problem is that the Java stuff needs a JRE to run, so for starters, 
you'll have to bundle a JRE.

The normal code sequence to load and run Java code from C/C++ code is to 
use "JNI" (the Java Native Interface) to create a virtual machine, and 
feed it code to execute.

However, in your case, where you have a C/C++ DLL that you want to ship, 
and have various entry points in it (which can be called in any sequence 
or selection) turn around and call Java code, you probably want to 
create some sort of "helper class" that'll load the VM once (on first 
invocation), and then invoke the Java code underneath.

In order to make this easier to encapsulate, your Java code should 
probably implement some standard interface, so that the boilerplate code 
to invoke it and pass parameters can be shared by the various library 
entry points..

So the short answer is again: yes, it can be done, but it might be 
painful and messy.
--
Shankar.

Thanks Shankar...really appreciate the input.

BH

"Shankar Unni" <shankar@cotagesoft.com> wrote in message
news:3dcff06b$1@newsgroups.borland.com...
> BH wrote:
>
> > We're new to java and wondering about the prospects of easing it into
> > our current non-java apps until they are eventually 100% java....
> >
> > Is it possible to "blend" java desktop or C/S app widgets (not
> > web/browser stuff) with a win32 app such that the java portions appear
> > to be part of the calling win32 app or dll?
>
> Not without some difficulty, but it's not impossible.
>
> The problem is that the Java stuff needs a JRE to run, so for starters,
> you'll have to bundle a JRE.
>
> The normal code sequence to load and run Java code from C/C++ code is to
> use "JNI" (the Java Native Interface) to create a virtual machine, and
> feed it code to execute.
>
> However, in your case, where you have a C/C++ DLL that you want to ship,
> and have various entry points in it (which can be called in any sequence
> or selection) turn around and call Java code, you probably want to
> create some sort of "helper class" that'll load the VM once (on first
> invocation), and then invoke the Java code underneath.
>
> In order to make this easier to encapsulate, your Java code should
> probably implement some standard interface, so that the boilerplate code
> to invoke it and pass parameters can be shared by the various library
> entry points..
>
> So the short answer is again: yes, it can be done, but it might be
> painful and messy.
> --
> Shankar.
>
>