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From: "Colby Nyce" <cnyce@mathworks.com>
Newsgroups: comp.lang.java.programmer
Subject: Trouble with JNI wrapper functions
Date: Thu, 8 Sep 2011 15:10:06 -0400
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Hi all,

I am trying to call Java methods from C++ code using the JNI wrapper 
functions that we have available in the "jmi" library, but I am having 
difficulty figuring out how to obtain one of the required input variables. 
I need to use any one of the "mljCall<type>Method" functions, such as:

mljCallVoidMethod
mljCallIntMethod
mljCallBooleanMethod
etc

These functions accept at least two parameters.  The first is a "jobject", 
and the second is a "jmethodID" (any additional arguments are treated as 
input parameters to your Java method).  I have been able to get an address 
to my Java method, but I am not sure how to get an appropriate "jobject" to 
use with this function.  The code I have boils down to this:

/**************************************************************************/
    jclass objectClass = mljFindClass("WebScopeInterfaceToJava");
    jmethodID webscopeMethod = mljGetMethod(objectClass, "voidMethod", 
"()V");
    jobject j_obj = // How do I get this?
    mljCallVoidMethod(j_obj,webscopeMethod);
/**************************************************************************/


Where do I get the correct "jobject" from?  Is this available from the 
global JVM or something?  I have looked through a lot of the source code, 
but I am finding it to be somewhat cryptic.  Please bear with me, I am 
completely new to JNI!

Thanks,
Colby
x7888