call c++ function in Java with input and output ar

I have a c++ code which has been connected to a visual basic user interface by someone else. Here is one of the functions code that connects c++ to visual basic:

   extern "C" void PASCAL EXPORT RCS( stAct* act,stResourceDirectory* resDir,   stCalendar* calendar, short  numOfAct, short numOfRes, short numOfCal, int nDataDate )
{
Network network;
short id;
Activity* p_act;
node<Activity>* p_node;

    // Setting
    network.create_calendars (calendar, numOfCal);
    network.set_data_date (nDataDate);
    set_activity(network, act, numOfAct );
// only for id, duration, and description   
    set_resource(network, act, resDir, numOfAct, numOfRes);
// create resource profile and add required resource for every activity

    network.CPM ();

    p_node = network.get_network_head_p();  

    while (p_node != NULL ) {
    p_act = p_node->refer_data();
    id = p_act->get_ID ();

    act[id].TF_in_CPM = p_act->get_TF_min ();
    act[id].FF_in_CPM = p_act->get_FF();
    act[id].EST_in_CPM = p_act->get_EST ();
    act[id].EFT_in_CPM = p_act->get_EFT ();
    act[id].LST_in_CPM = p_act->get_LST ();
    act[id].LFT_in_CPM = p_act->get_LFT ();
    p_node = p_node->get_link();
    }
    network.RCS();  
p_node = network.get_network_head_p();  

while (p_node != NULL ) {
    p_act = p_node->refer_data();
    id = p_act->get_ID ();

    act[id].TF_in_RCS = p_act->get_TF_min ();
    act[id].FF_in_RCS = p_act->get_FF();
    act[id].EST_in_RCS = p_act->get_EST ();
    act[id].EFT_in_RCS = p_act->get_EFT ();
    act[id].LST_in_RCS = p_act->get_LST ();
    act[id].LFT_in_RCS = p_act->get_LFT ();

    p_node = p_node->get_link();
    }
}

I want to replace the visual basic part with a Java GUI and it seems confusing for me to write the connection code. Is there anyone who can help me call three c++ functions with passing arguments to the native method and receiving results from it, by JNA/ SWIG/ Runtime or any other methods you think it would work easier and better?

Here is an instructional example to help get you started. In this snippet, Java2Win64 is the DLL that contains the native code to execute. Function functionMaryam() takes 1 param as int and returns an int. Easy to expand for any data type. public class JnaExampleMaryam {

// ------------------------------------------
// Java2Win.class
// ------------------------------------------
public interface Java2Win extends Library {
    Java2Win call = (Java2Win) Native.loadLibrary("Java2Win64", Java2Win.class);
    int functionMaryam(int i);
}
// ------------------------------------------

// ------------------------------------------
// Test
// ------------------------------------------
public static void main(final String args[]) throws Exception {
    final File file = new File("rootToDLL", "Java2Win64.dll");
    LibraryLoader.loadLibrary(file);

    int result = Java2Win.call.functionMaryam(42);
}
// ------------------------------------------