Invalid indirect reference 0x416f68a0 in decodeIndirectRef

Issue

I've seen plenty of questions about exactly the same error, but none of them seems to be trying to do this simple thing and still fail.

I have in my class header, as private members:

static JNIEnv* env;
static jclass copterServiceClass;
static jmethodID mavlinkMsgMethod;

Then in the source for that class:

JNIEnv* JU_Calls::env = 0;
jclass JU_Calls::copterServiceClass = 0;
jmethodID JU_Calls::mavlinkMsgMethod = 0;

bool JU_Calls::setupJNICalls() {

    if (cached_jvm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6) != JNI_OK) {
        __android_log_print(ANDROID_LOG_ERROR, TAG, "Unable to get Java Env from cached JavaVM");
        return -1;
    }

    jclass dataClass = env->FindClass("eu/deye/copterdroidair/copterdroidair/Services/CopterService");
    copterServiceClass = (jclass) env->NewGlobalRef(dataClass);
    mavlinkMsgMethod = env->GetMethodID(copterServiceClass, "MavlinkMsg", "(Ljava/lang/String;)V");

    jobject javaObjectRef = env->NewObject(copterServiceClass, mavlinkMsgMethod);
    jstring msg = env->NewStringUTF("aaaa");
    env->CallVoidMethod(javaObjectRef, mavlinkMsgMethod, msg);

    return true;
}

Note: cached_jvm is assigned at JNI_OnLoad.

It fails with the aforementioned error when executing NewObject.

Invalid indirect reference 0x416f68a0 in decodeIndirectRef

I tried passing NULL to the CallVoidMethod as the message, as seen on other's questions, but as it's logical, the problem is before, so useless.

Hope you can help me, as always, great SO masters ;)

EDIT: While I think Bangyno answer is the right one, what I've eventually done to solve the problem as quickest as possible, was to declare the Java Methods that would be called from C++ as static. That way I don't have to call the constructor, and everything makes a lot more sense. Because the Java class to which I was calling, was an Android Service, thus calling the constructor was erroneous for sure.

Apart from declaring the Java method static, the resulting C++ code results as follows:

jclass copterServiceClass = env->FindClass("eu/deye/copterdroidair/copterdroidair/Services/CopterService");
jmethodID mavlinkMsgMethod = env->GetStaticMethodID(copterServiceClass, "MavlinkMsg", "(ILjava/lang/String;)V");
jstring msg = env->NewStringUTF(str);
env->CallStaticVoidMethod(copterServiceClass, mavlinkMsgMethod, severity, msg);
env->DeleteLocalRef(msg);

Is very important not to forget the last line, because otherwise it will fill your JNI table and crash.

Solution

Here I want to discuss is the error message:

Invalid indirect reference 0x416f68a0 in decodeIndirectRef

It means you give the wrong argument, the second one "mavlinkMsgMethod". In my experience, if you change "mavlinkMsgMethod" to a number such as "5", the 0x416f68a0 will change to 0x5.

The right way to use newObject is use to invoke the constructor. It should look like this, just a sample:

jclass dataClass = env->FindClass("eu/deye/copterdroidair/copterdroidair/Services/CopterService");
mavlinkMsgMethod = env->GetMethodID(copterServiceClass, "<init>", "(Ljava/lang/String;)V");
jstring str = env->NewStringUTF("testing");    
jobject javaObjectRef = env->NewObject(copterServiceClass, mavlinkMsgMethod, str);

Answered By - Bangyno