AppletTalk.com Java discussions newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Calling a C++ dll from Java          AppletTalk.com Forum Index -> comp.lang.java.tech View previous topic :: View next topic   Author Message Samagna Guest Posted: Tue Sep 07, 2004 10:32 am    Post subject: Calling a C++ dll from Java 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.... 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 should I place my dll to compile it? Quick reply would be appreicated. Thanks in advance. Samagna Back to top Chris Uppal Guest Posted: Tue Sep 07, 2004 11:55 am    Post subject: Re: Calling a C++ dll from Java Samagna wrote: Quote: I need to call a function that is there in a C++ dll. The arguments to the function are 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 'structs'. 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. The Sun JNI tutorial at: http://java.sun.com/docs/books/tutorial/native1.1/index.html should get you started on JNI programming. It's not difficult if you keep it simple, and it doesn't sound as if you need to do anything very complicated for these purposes. -- chris Back to top Robert kebernet Cooper Guest Posted: Sun Dec 19, 2004 11:35 pm    Post subject: Re: Calling a C++ dll from Java Depending on what you are trying to do, the IBM Java-COM bridge can be a MUCH 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-ish API's quite successfully. http://www-106.ibm.com/developerworks/library/j-intbridge/ Back to top Tilman Bohn Guest Posted: Mon Dec 20, 2004 11:48 pm    Post subject: Re: Calling a C++ dll from Java [f'up2 cljp] In message <1103499319.457151.242540 (AT) f14g2000cwb (DOT) googlegroups.com>, Robert kebernet Cooper wrote on 19 Dec 2004 15:35:19 -0800: [...] Quote: http://www-106.ibm.com/developerworks/library/j-intbridge/ This looks very interesting, I hadn't known about that! Could 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 Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         AppletTalk.com Forum Index -> comp.lang.java.tech All times are GMT Page 1 of 1   Jump to: Select a forum Java Newsgroups----------------Java DiscussionsWeb-based java games comp.lang.java 3D Graphics API's for Java Java: Support and criticism Java System Announcements comp.lang.java.api JavaBeans Java and CORBA Java and Databases comp.lang.java.developer Java GUI Toolkits Java Help comp.lang.java.javascript JVM, native methods and hardware comp.lang.java.misc Java Language Programming Security and Java comp.lang.java.setup Java Software Tools comp.lang.java.tech ibm.software.java.linux  Non-English Java Newsgroups----------------Java Language (German)Language Java (Français)Java (Italian)  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.