Embed Java code into your native apps

/** File main.c **/
#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <X11/Intrinsic.h>
#define IN_PORT  9970 /* Must be the same than outPort in SwingMenu.java */
int initInputSocket() {
   int s;
   struct sockaddr_in addIN;
   /*
    * Creating a socket for listening to the requests coming from the JVM.
    */
   if ( (s = socket(AF_INET, SOCK_DGRAM, 0)) < 0 ) {
      perror ("initInputSocket: socket()");
      exit(2);
   }
   addIN.sin_family = AF_INET;
   addIN.sin_port    = IN_PORT;
   addIN.sin_addr.s_addr = INADDR_ANY;
   if ( bind(s, (struct sockaddr *)&addIN, sizeof(addIN) ) < 0 
) {
      perror ("initInputSocket: bind()");
      close(s);
      exit(3);
   }
  return(s);
}
/*
 * Function to proceed the packet received
 */
proceedJavaClientRequest(XtPointer clientData, int *socket, XtInputId *id)
{
  ssize_t size;
  char buf[256];
  /*
   * Note that when proceedJavaClientRequest() is called there is always something to read on the socket.
   * Hence the call to recv() is not blocking.
   */
  size = recv(*socket, buf, sizeof(buf), 0);
  if ( strncmp("CreateOGLWindow", buf, size)==0 ) createOGLwindow(NULL);
  if ( strncmp("Animate", buf, size)==0 )         toggleMotionFromJVM();
}
static XtAppContext app;
static String       fallbackResources[] = {
    "*title: Motif GUI.",
    "*glxarea*width: 400", "*glxarea*height: 400", NULL
};
main (int argc, char *argv[])
{
   int    inputSocket;
   Widget toplevel;
   /*
     * The main thread of the application will act as a datagram socket server.
     * The JVM will be the client. This way the Java code will be able to call
     * some native functions and make sure they are executed in the main thread.
     */
   inputSocket = initInputSocket();
   /*
    * Create the top level shell.
    */
   toplevel = XtVaAppInitialize(&app,
                                "SWING-MOTIF",
                                NULL,
                                0,
                                &argc,
                                argv,
                                fallbackResources,
                                NULL,0);
   /*
    * Adding our socket to the input sources checked by the Xtoolkit.
    */
   XtAppAddInput(app, inputSocket, XtInputReadMask,
             proceedJavaClientRequest, NULL);
   /*
    * Listen for events.
    * This must be the only blocking call in the main thread.
    */
   XtAppMainLoop(app);
}