how to save a c++ object in java object and use it

http://blog.csdn.net/luoshengyang/article/details/6817933

save:

static void android_os_MessageQueue_setNativeMessageQueue(JNIEnv* env, jobject messageQueueObj,  

        NativeMessageQueue* nativeMessageQueue) {  

    env->SetIntField(messageQueueObj, gMessageQueueClassInfo.mPtr,  

             reinterpret_cast<jint>(nativeMessageQueue));  
}  

reuse:

nativePollOnce(mPtr, nextPollTimeoutMillis);  

static void android_os_MessageQueue_nativePollOnce(JNIEnv* env, jobject obj,  

        jint ptr, jint timeoutMillis) {  

    NativeMessageQueue* nativeMessageQueue = reinterpret_cast<NativeMessageQueue*>(ptr);  

    nativeMessageQueue->pollOnce(timeoutMillis);  

}