Function CreateJavaCallbackData

Core/ClientSMLSWIG/Java/JavaCallbackByHand.h:218–254

Collect the Java values into a single object which we'll register with our local event handler. When this handler is called we'll unpack the Java data and make a callback to the Java process.

// Collect the Java values into a single object which we'll register with our local event handler.
// When this handler is called we'll unpack the Java data and make a callback to the Java process.
static JavaCallbackData* CreateJavaCallbackData(bool storeAgent, JNIEnv* jenv, jclass jcls, jlong jarg1, jint jarg2, jobject jarg3, jobject jarg4, char const* pMethodName, jobject jarg6)
{
    // The trick here is we collect up all of the Java information and store that as the callback data
    // for our local handler.  When our handler is called we'll unpack the data and make the Java callback.
    
    // This is critical: we need to make our references to the objects "global".
    // Otherwise the JNI objects will be deleted when we exit this method making them useless
    // to us when the eventual callback occurs.
    jobject jglobal3 = jenv->NewGlobalRef(jarg3) ;  // The Java agent or kernel object
    jobject jglobal4 = jenv->NewGlobalRef(jarg4) ;  // The Java object which will handle this callback
    jobject jglobal6 = jenv->NewGlobalRef(jarg6) ;  // Arbitrary object passed back to the caller
    
    // Get the method name from the Java string
    // We used to pass this in as a parameter to the callback, but now its imbedded in the interface definition.
    //const char *pMethodName = jenv->GetStringUTFChars(jarg5, 0);
    
    // Record the virtual machine we are using
    JavaVM vm ;
    JavaVM* pvm = &vm ;
    jint result = jenv->GetJavaVM(&pvm) ;
    
    if (result != 0)
    {
        printf("Error getting Java VM\n") ;
        return 0 ;
    }
    
    JavaCallbackData* pJavaData = new JavaCallbackData(pvm, jenv, storeAgent ? jglobal3 : 0, storeAgent ? 0 : jglobal3, jglobal4, pMethodName, jglobal6) ;
    
    // Save the callback data so we can free it later
    callbackdatas.push_back(pJavaData);
    
    // Release the string we got from Java
    //jenv->ReleaseStringUTFChars(jarg5, pMethodName);
    
    return pJavaData ;
}

// This is the C++ handler which will be called by clientSML when the event fires.
// Then from here we need to call back to Java to pass back the message.