diff --git a/hello-jniCallback/app/src/main/cpp/hello-jnicallback.c b/hello-jniCallback/app/src/main/cpp/hello-jnicallback.c
index 86738e720..452a34f4a 100644
--- a/hello-jniCallback/app/src/main/cpp/hello-jnicallback.c
+++ b/hello-jniCallback/app/src/main/cpp/hello-jnicallback.c
@@ -33,8 +33,8 @@ static const char *kTAG = "hello-jniCallback";
 // processing callback to handler class
 typedef struct tick_context {
   JavaVM *javaVM;
-  jclass jniHelperClz;
-  jobject jniHelperObj;
+  jclass jniHandlerClz;
+  jobject jniHandlerObj;
   jclass mainActivityClz;
   jobject mainActivityObj;
   pthread_mutex_t lock;
@@ -88,26 +88,26 @@ Java_com_example_hellojnicallback_MainActivity_stringFromJNI(JNIEnv *env,
 
 /*
  *  A helper function to show how to call
- *     java static functions JniHelper::getBuildVersion()
- *     java non-static function JniHelper::getRuntimeMemorySize()
+ *     java static functions JniHandler::getBuildVersion()
+ *     java non-static function JniHandler::getRuntimeMemorySize()
  *  The trivial implementation for these functions are inside file
- *     JniHelper.java
+ *     JniHandler.java
  */
 void queryRuntimeInfo(JNIEnv *env, jobject instance) {
   // Find out which OS we are running on. It does not matter for this app
   // just to demo how to call static functions.
-  // Our java JniHelper class id and instance are initialized when this
+  // Our java JniHandler class id and instance are initialized when this
   // shared lib got loaded, we just directly use them
   //    static function does not need instance, so we just need to feed
   //    class and method id to JNI
   jmethodID versionFunc = (*env)->GetStaticMethodID(
-      env, g_ctx.jniHelperClz, "getBuildVersion", "()Ljava/lang/String;");
+      env, g_ctx.jniHandlerClz, "getBuildVersion", "()Ljava/lang/String;");
   if (!versionFunc) {
     LOGE("Failed to retrieve getBuildVersion() methodID @ line %d", __LINE__);
     return;
   }
   jstring buildVersion =
-      (*env)->CallStaticObjectMethod(env, g_ctx.jniHelperClz, versionFunc);
+      (*env)->CallStaticObjectMethod(env, g_ctx.jniHandlerClz, versionFunc);
   const char *version = (*env)->GetStringUTFChars(env, buildVersion, NULL);
   if (!version) {
     LOGE("Unable to get version string @ line %d", __LINE__);
@@ -120,8 +120,8 @@ void queryRuntimeInfo(JNIEnv *env, jobject instance) {
   (*env)->DeleteLocalRef(env, buildVersion);
 
   // Query available memory size from a non-static public function
-  // we need use an instance of JniHelper class to call JNI
-  jmethodID memFunc = (*env)->GetMethodID(env, g_ctx.jniHelperClz,
+  // we need use an instance of JniHandler class to call JNI
+  jmethodID memFunc = (*env)->GetMethodID(env, g_ctx.jniHandlerClz,
                                           "getRuntimeMemorySize", "()J");
   if (!memFunc) {
     LOGE("Failed to retrieve getRuntimeMemorySize() methodID @ line %d",
@@ -136,8 +136,8 @@ void queryRuntimeInfo(JNIEnv *env, jobject instance) {
 /*
  * processing one time initialization:
  *     Cache the javaVM into our context
- *     Find class ID for JniHelper
- *     Create an instance of JniHelper
+ *     Find class ID for JniHandler
+ *     Create an instance of JniHandler
  *     Make global reference since we are using them from a native thread
  * Note:
  *     All resources allocated here are never released by application
@@ -155,13 +155,13 @@ JNIEXPORT jint JNICALL JNI_OnLoad(JavaVM *vm, void *reserved) {
 
   jclass clz =
       (*env)->FindClass(env, "com/example/hellojnicallback/JniHandler");
-  g_ctx.jniHelperClz = (*env)->NewGlobalRef(env, clz);
+  g_ctx.jniHandlerClz = (*env)->NewGlobalRef(env, clz);
 
-  jmethodID jniHelperCtor =
-      (*env)->GetMethodID(env, g_ctx.jniHelperClz, "<init>", "()V");
-  jobject handler = (*env)->NewObject(env, g_ctx.jniHelperClz, jniHelperCtor);
-  g_ctx.jniHelperObj = (*env)->NewGlobalRef(env, handler);
-  queryRuntimeInfo(env, g_ctx.jniHelperObj);
+  jmethodID jniHandlerCtor =
+      (*env)->GetMethodID(env, g_ctx.jniHandlerClz, "<init>", "()V");
+  jobject handler = (*env)->NewObject(env, g_ctx.jniHandlerClz, jniHandlerCtor);
+  g_ctx.jniHandlerObj = (*env)->NewGlobalRef(env, handler);
+  queryRuntimeInfo(env, g_ctx.jniHandlerObj);
 
   g_ctx.done = 0;
   g_ctx.mainActivityObj = NULL;
@@ -169,7 +169,7 @@ JNIEXPORT jint JNICALL JNI_OnLoad(JavaVM *vm, void *reserved) {
 }
 
 /*
- * A helper function to wrap java JniHelper::updateStatus(String msg)
+ * A helper function to wrap java JniHandler::updateStatus(String msg)
  * JNI allow us to call this function via an instance even it is
  * private function.
  */
@@ -183,7 +183,7 @@ void sendJavaMsg(JNIEnv *env, jobject instance, jmethodID func,
 /*
  * Main working thread function. From a pthread,
  *     calling back to MainActivity::updateTimer() to display ticks on UI
- *     calling back to JniHelper::updateStatus(String msg) for msg
+ *     calling back to JniHandler::updateStatus(String msg) for msg
  */
 void *UpdateTicks(void *context) {
   TickContext *pctx = (TickContext *)context;
@@ -199,8 +199,8 @@ void *UpdateTicks(void *context) {
   }
 
   jmethodID statusId = (*env)->GetMethodID(
-      env, pctx->jniHelperClz, "updateStatus", "(Ljava/lang/String;)V");
-  sendJavaMsg(env, pctx->jniHelperObj, statusId,
+      env, pctx->jniHandlerClz, "updateStatus", "(Ljava/lang/String;)V");
+  sendJavaMsg(env, pctx->jniHandlerObj, statusId,
               "TickerThread status: initializing...");
 
   // get mainActivity updateTimer function
@@ -211,7 +211,7 @@ void *UpdateTicks(void *context) {
   const struct timeval kOneSecond = {(__kernel_time_t)1,
                                      (__kernel_suseconds_t)0};
 
-  sendJavaMsg(env, pctx->jniHelperObj, statusId,
+  sendJavaMsg(env, pctx->jniHandlerObj, statusId,
               "TickerThread status: start ticking ...");
   while (1) {
     gettimeofday(&beginTime, NULL);
@@ -236,12 +236,12 @@ void *UpdateTicks(void *context) {
     if (sleepTime.tv_sec <= 1) {
       nanosleep(&sleepTime, NULL);
     } else {
-      sendJavaMsg(env, pctx->jniHelperObj, statusId,
+      sendJavaMsg(env, pctx->jniHandlerObj, statusId,
                   "TickerThread error: processing too long!");
     }
   }
 
-  sendJavaMsg(env, pctx->jniHelperObj, statusId,
+  sendJavaMsg(env, pctx->jniHandlerObj, statusId,
               "TickerThread status: ticking stopped");
   (*javaVM)->DetachCurrentThread(javaVM);
   return context;