JNI question (javai.lib????) 1

[brownie124]

Hi,

I have now seen a couple of examples for using the JNI to call a functions within a dll. In both samples the makefile said to link with javai.lib. I do not see that on my system anywhere. What is it? Do I really need it? If so, where do I get it?

Thanks,
- Brownie

 

[hologram]

Brownie, I am using Windows 2000, jdk1.3.1 and jdk1.4.2. I don't have the file either. I think it's not needed on Windows.

javai.lib is used on Solaris

I think Windows uses "...\jdk...\lib\jvm.lib". But I haven't used JNI myself, so I'm not sure.

 

[palbano]

Yes jvm.lib is the correct library to link for JNI.

-pete

 

[maxpower1]

brownie,
to use jni, you need to:-
1. compile your java class, Test.java -> Test.class
2. use javah.exe (should come with jdk) to create the h file
--> $javah.exe Test.class
3. This should create C/C++ header file.
4. You need to create the *.C/*.cpp file
5. build the dll
6. In java file, to load the library, use
System.loadLibrary("your dll&quot

7. make sure the dll is in \windows\system32 dir



~za~
You can't bring back a dead thread!

 

[palbano]

maxpower1 may be correct if your use of JNI is restricted to going from Java to C/C++, i am not 100% sure.

If you want to call back into the Java environment from C/C++ you need to link in jvm.lib. This is what i assumed you were needing since you posted the question in the first place.

-pete

 

[maxpower1]

you,re right pete. it is restricted to c/c++

~za~
You can't bring back a dead thread!

 

[brownie124]

Guys, thanks for the help, I am all set. Have it working beautifully.

 

[metalscreamer]

Hi,

I figured that you had to link jvm.lib but I am glad to be sure of that now because I was looking for javai.lib as well, but now at least I know that is not the solution to my problem. Does anybody have any idea why when I call JNI_CreateJavaVM(&jvm, (void**)&env, &vm_args) it always returns 0 and the JVM instance is never created. I am new to JNI and I just want to create a simple install for my java applications and it looks like JNI is the best way to go. I'd really appreciate any help.

Thanks