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Java Calling the miniLab 1008 DLL's

Posted on 2003-03-12
Medium Priority
Last Modified: 2007-12-19
An interface board called the miniLab 1008 is controlled via DLL (MccMinilab.DLL) calls to read or set the values of it's I/O ports.

The documentation says that the DLL's functions can be called by using MS Visual C++, or MS Visual BASIC.

Is there an -easy- way to call these DLL functions through Java? If you wouldn't mind looking at the functions and things in the DLL documentation, and seeing how easy it would be first, before attempting to answer, because if it is too hard, I suppose learning VB or VC++ won't be too hard.

Question by:Lab_Rat
LVL 86

Expert Comment

ID: 8119119
You will have to use JNI to load the DLL. Therefore you will have two DLLs, one created by your JNI routines, and the Minlab one. See http://java.sun.com/docs/books/tutorial/native1.1/

Author Comment

ID: 8127380
Hiyah, thanks for the URL, I have one major concern!

If you take a look at this list from the site you gave:

Writing native methods for Java programs is a multi-step process.

1 : Begin by writing the Java program. Create a Java class that declares the native method; this class contains the declaration or signature for the native method. It also includes a main method which calls the native method.
2 : Compile the Java class that declares the native method and the main method.
3 : Generate a header file for the native method using javah with the native interface flag -jni. Once you've generated the header file you have the formal signature for your native method.
4 : Write the implementation of the native method in the programming language of your choice, such as C or C++.
5 : Compile the header and implementation files into a shared library file.
6 : Run the Java program.

All is fine until step 4!
Write the implementation of the native method???
I would try, but unfortunatly it is a DLL that is already written (by a company that most certainly give out source code).

My question is slightly changed therefore:

Can an -existing- DLL be called by the JNI?
LVL 86

Accepted Solution

CEHJ earned 1000 total points
ID: 8127415
>>Can an -existing- DLL be called by the JNI?

Yes. You load the dll in a platform-specific way and then call the methods.

Expert Comment

ID: 9058743
This old question needs to be finalized -- accept an answer, split points, or get a refund.  For information on your options, please click here-> http:/help/closing.jsp#1 
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Expert Comment

ID: 9714410
No comment has been added lately, so it's time to clean up this TA.
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