🚀 go-pugleaf

Roger Woodward <rogerw@woodwardassoc.co.uk> wrote in message
news:3c7e6bc5_2@dnews...
> Simple question from a non Java person.
> How does Java call functions residing either within a DLL or OCX
component.
For DLLs using JNI, for OCXs either using JNI or one of the available
ActiveX / COM  - Java bridges.

> Is this a simple process and are there any obvious pitfalls.
It's a bit of a messy process, IMO. The reccomended procdeure is to define
your Java class, marking the desired methods as native and then run javah
over the class file. This will produce a C header file for you, which
obviously needs implementing. There is a Delphi translation of the JNI API
available at JEDI (www.delphi-jedi.org) which lessens the pain if you don't
happen to like C / C++ and can live with being restricted to Win / Linux,
but it doesn't (yet) have an automatic interface generator :(

> I know that JNI exists but nothing about it (Ive an idea that this is what
I
> need to investigate) so if you know of a good web reference as a starting
> point for reading I would be very grateful.
http://java.sun.com/docs/books/tutorial/native1.1/index.html
http://java.sun.com/products/jdk/faq/jnifaq.html

There is also some information in the standard SDK docs.

Also, FWIW, I heard that some changes may have been made for JNI in JDK 1.4,
but that may be a faulty memory (I haven't yet played with 1.4, the shame,
the shame).

hth
Owen