Main.java, the class which calls the C function, passing the WebSiteVisit object

/**
*
* @author thomas
*/
public class Main {

private native void nativePrintObject(WebSiteVisit wsv);
/** Creates a new instance of Main */
public Main() {
}

static {
    System.load("/home/thomas/testlib/HelloWorldNative/dist/HelloWorldNative.so");
}
/**
 * @param args the command line arguments
 */
public static void main(String[] args) {
    Main me = new Main();
    WebSiteVisit a, b;
    a = new WebSiteVisit("index.html", "subpage.html", 0x32389283);
    b = new WebSiteVisit("subpage.html", "pagetwo.html", 0x32399283);

    me.nativePrintObject(a);
    me.nativePrintObject(b);
}

}

WebSiteVisit.java, the passed object:

package helloworld;

/**
*
* @author thomas
*/
public class WebSiteVisit {
  /** URL of the web page that linked user to this one */
  public String refererURL;
  public String pageVisited;
  public int ipAddress;

  /** Creates a new instance of WebSiteVisit */
  public WebSiteVisit() {
  }

  public WebSiteVisit(String referer, String page, int ip) {
      this.refererURL = referer;
      this.ipAddress = ip;
      this.pageVisited = page;
  }

}

The c function which receive the object:

JNIEXPORT void JNICALL Java_helloworld_Main_nativePrintObject
(JNIEnv *env, jobject ths, jobject wsv)
{
  jfieldID fid;
  jint ipAddress;
  jstring jPageVisited;
  char *pageVisited;
  jstring jRefererURL;
  char *refererURL;
  jclass c;

  c = (*env)->GetObjectClass(env, wsv);
  fid = (*env)->GetFieldID(env, c, "ipAddress", "I");
  ipAddress = (*env)->GetIntField(env, wsv, fid);
  printf("  wsv.ipAddress = %d.%d.%d.%dn",
      ( ipAddress & 0xff000000 ) >> 24,
      ( ipAddress & 0x00ff0000 ) >> 16,
      ( ipAddress & 0x0000ff00 ) >> 8,
      ipAddress & 0x000000ff);
  fid = (*env)->GetFieldID(env, c, "pageVisited", "Ljava/lang/String;");
  if(!fid) {
      return;
  }
  jPageVisited = (*env)->GetObjectField(env, wsv, fid);
  pageVisited = (*env)->GetStringUTFChars(env, jPageVisited, 0);

  if(!pageVisited) {
      return;
  }
  printf("  wsv.pageVisted = %sn", pageVisited);

  (*env)->ReleaseStringUTFChars(env, jPageVisited, pageVisited);

  fid = (*env)->GetFieldID(env, c, "refererURL", "Ljava/lang/String;");
  if(!fid) {
      return;
  }
  jRefererURL = (*env)->GetObjectField(env, wsv, fid);
  refererURL = (*env)->GetStringUTFChars(env, jRefererURL, 0);
  printf("  wsv.refererURL = %sn", refererURL);

  (*env)->ReleaseStringUTFChars(env, jRefererURL, refererURL);
}