Re: java and fc16

[Philip Nienhuis]

Daniel J Sebald wrote:
> On 11/25/2012 06:12 PM, Philip Nienhuis wrote:
> > Michael Godfrey wrote
> > > On 11/25/12 11:36 PM, Philip Nienhuis wrote:
> > > > I had the same error (jni.h not found) and solved it by, before running
> > > > ./configure, setting JAVA_HOME to the place where the Java stuff lives.
> > > I thought about that, but since in my system at least, there
> > > seemed to be java stuff here there and everywhere with lots of
> > > symlinks, I decided on a more specific patch. This was not meant to
> > > be a real solution, just a test.
> >
> > Yeah, Java installation isn't quite standardized across distros and
> > operating systems :-(
>
> I know little about Java so started reading, and just got to this topic.
> There's was a push to standardized, then withdrawn. Now there is the
> Oracle de facto standard.

Ahum, "de facto standard".... you forget that each distro and OS 
develops its own "standard" to hide the Java stuff. Fedora and 
Mandriva/Mageia look quite similar, but on Ubuntu the Java JDK is in a 
different place; on Windows it is again somewhere else, Mac OSX largely 
amended the naming convention.

> Anyway, for those of us unfamiliar to Java, what does the Java package /
> scripts do? I see the NEWS item about it. It seems like it creates
> dialog boxes.

Yes the ????dlg scripts were made by Martin Hepperle as they didn't 
exist (yet) in Octave, he needed them and they could very easily be made 
using a bit of Java code and some C++.
Maybe these dialog functions have to be dropped once they are supported 
natively in Qt or OpenGL.

The Java package/system allows you to invoke many many Java libs 
belonging to the Java system itself, and many many libs written by third 
parties; the latter may be OSS or proprietary. There are Java libraries 
and packages for about anything conceivable; not that they are all as good.
Anyway Java doesn't have to be alone. Maybe one day there'll be a Python 
package allowing Octave to link to the many Python libs out there. Or a 
bridge to some other cross-platform language.

To me Java is just a means to be able to use pre-baked libraries made 
for specific tasks that would have taken me much more time would I have 
coded in e.g., C++. Nothing more, nothing less.

I used it to develop the spreadsheet I/O routines, as there are many 
good quality Java solutions out there. In my case it was a simple choice 
between having to invest a lot of time in obtaining a rigid proficiency 
in C++, autotools and gdb, or just spending my limited time for Octave 
developing easily debugged Octave script language and leaving the lower 
level code to third parties.

> Does it create Java Byte Code? Or is it a means to interact with already
> running Java Byte Code? Are there any security issues by supporting Java
> in this way?

The second, interacting with pre-compiled byte code.
Oh and I wouldn't run a web server written in Java.

> There are some aspects of the Octave Java support written in C/C++. Is
> that needed so that the Java support can be cross-platform?

You mean the Octave-Java bridge proper. Yes I think so. Michael Goffioul 
(the creator of Octave's Java bridge) is the expert here.

Philip