How to instantiate a java object (using JNI)?(n'more)

Question

hey bschauwe, thanks for your last post, you were guessing but your 4th guess was right on the money of how id like to do it.
"4. An alternative way to return data to java from C is to instantiate a java object (using JNI), then use JNI to call that object's setters, then return the object at the end of the C routine."
I know now how to get the object's setters, I am just unsure how to instantiate a java object from the native C code using JNI. Also you said to returnt he object at the end of the c routine, that is just a good ol' return statement right? no other functions to release memory or anything are needed? So basically it would be something like:
JNIEXPORT jobject retObj JNICALL Java_AbfaRegion_getJSourceData
  (JNIEnv *env, jobject thisObj)
        //instantiate the java object on retObj????
        //call setters with values from the c structures...
        //return retObj??? no other memory releasing needed?
}Thanks again for all your help,
Shane

Answer 1

K sounds straight forward enough, the index in my book had nothing on <init> and I wasnt aware of the NewObject call. So my final (well for demonstration purposes) code should look something like:
JNIEXPORT jobject retObj JNICALL Java_AbfaRegion_getJSourceData
  (JNIEnv *env, jobject thisObj)
     jclass clazz;
     jclass clazzTemp;
     jmethodID mid;
     jint val;
     jobject tempObj;
        //first instanciate the object
     clazz = (*env)->GetObjectClass(env, retObj);
     mid  = (*env)->GetMethodID(env, clazz, "<init>", "()V");     
        //Get Object
     tempObj = (*env)->NewObject(env, clazz, mid);
        //get Class reference to instantiated class
     clazzTemp = (*env)->GetObjectClass(env, tempObj);
        //Start calling setters to set the object up.
     mid = (*env)->GetMethodID(env, clazzTemp, "SetHeight", "(I)V");
     (*env)->CallVoidMethod(env,tempObj, mid, struct->myHeight);
        //set more members ...
        //return the object back to java with its members filled out.
        //before returning do I need to call (*env)->DeleteLocalRef(tempObj); ??
        return tempObj;
}So is this how i do it for a function that is nativly defined as:
public native JSources getJSourceData();?
if this is right, then im cooking, and cannot thank you enough!
-Shane