Java call C DLL

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I need to call a function that is there in a C ++ DLL. The arguments The function are struct and string. The return type is void. Also I Donot have any rights to change the DLL and I have to use as it is .... So here goes my questions: 1. How to pass a struct variable from Java To a function in DLL. 2. The function returns void and the second Argument is the output variable which I need to use. So is there Anyway, that call by reference can be used from Java? 3. Where shocould I place my DLL to compile it? Quick Reply wocould be appreicated. Thanks in advance. Samagna Samagna

Samagna

	#2
Chris Uppal posts: N/	Re: calling a C ++ DLL from Java Samagna wrote: > I need to call a function that is there in a C ++ DLL. The arguments > The function is struct and string. You can't, I'm afraid. Java does not have the ability to call arbitrary code From an arbitrary DLL, nor does it understand's s '. So you have to be a bit more indirect. What you will have to do is write your Own C or C ++ code which follows the JNI conventions, and which therefore/CAN/ Be called from Java, and then call the other DLL from that. TheSunJNI tutorial: Http://java.sun.com/docs/books/tutor...1.1/index.html Shocould get you started on JNIProgramming. It's not difficult if you keep it Simple, And it doesn' t sound as if you need to do anything very complicated These purposes. -- Chris Chris Uppal

Chris Uppal

, PM	#3
tor Iver wilhelmsen posts: N/A	re: calling a C ++ DLL from Java (samagna) writes: I need to call a function that is there in a C ++ DLL. the arguments to the function are struct and string. the return type is void. also I donot have any rights to change the DLL and I have to use as it is .... you need to make an intermediate layer in JNI that convert Java arguments into the necessary C ++ arguments. since JAVA does not have "out" parameters, you need to use a return value of some sort from your Java Native method. tor Iver wilhelmsen

Tor Iver wilhelmsen

09-08-2004, PM	#4
Stian Bakken posts: N/	Re: calling a C ++ DLL from Java There are using cial software that will wrap. DLL's for you. Here are two: Http://www.excelsior-usa.com/xfunction.html Http://www.jniwrapper.com/index.jsp Disclause: I have not tried any of these, but they might suit your needs. Good luck, Stian "Samagna" <> wrote in message News: Om... > I need to call a function that is there in a C ++ DLL. The arguments > The function are struct and string. The return type is void. Also I > Donot have any rights to change the DLL and I have to use as it is .... > So here goes my questions: 1. How to pass a struct variable from Java > To a function in DLL. 2. The function returns void and the second > Argument is the output variable which I need to use. So is there > Anyway, that call by reference can be used from Java? 3. Where shocould > I place my DLL to compile it? > > Quick reply wocould be appreicated. > Thanks in advance. > Samagna Stian Bakken

Stian Bakken

12-19-2004, PM	#5
Robert kebernet Cooper posts: N/	Re: calling a C ++ DLL from Java Depending on what you are trying to do, IBM JAVA-com bridge can be a much easier way of moving data between the two than hand building JNI stuff. I have used this with Microsoft mappoint And some Other MS-ishAPI'sQuite successfully. Http://www-106.ibm.com/developerwork...y/j-intbridge/ Robert kebernet Cooper

Robert kebernet Cooper

12-20-2004, PM

#6

Tilman Bohn posts: N/A

re: calling a C ++ DLL from Java [f'up2 cljp] in message <. COM>, Robert kebernet Cooper wrote on 19 Dec 2004 15:35:19-0800: [...] http://www-106.ibm.com/developerwork...y/j-intbridge/ This looks very interesting, I hadn't known about that! Cocould come in very handy indeed in an upcoming project, so thanks from me for that pointer! -- cheers, Tilman 'Boy, life takes a long time to live... '-- Steven Wright Tilman Bohn