2.8.md

//回调，包括子线程回调
JNIInvokeMethod jniInvokeMethod = new JNIInvokeMethod();
jniInvokeMethod.nativeCallback(new ICallbackMethod() {
    @Override
    public void callback() {
        Log.d(TAG, "callback: " + Thread.currentThread().getName());
    }
});
jniInvokeMethod.nativeThreadCallback(new IThreadCallback() {
    @Override
    public void callback() {
        Log.d(TAG, "callback: " + Thread.currentThread().getName());
    }
});

public interface ICallbackMethod {
    void callback();
}

public interface IThreadCallback {
    void callback();
}

public class JNIInvokeMethod extends BaseOperation {
    @Override
    public void invoke() {

    }

    public native void nativeCallback(ICallbackMethod mICallbackMethod );
    public native void nativeThreadCallback(IThreadCallback mIThreadCallback);
}

static jclass threadClazz;
static jmethodID threadMethod;
static jobject threadObject;

extern "C"
JNIEXPORT void JNICALL
Java_com_jdqm_ndktutorials_jni_JNIInvokeMethod_nativeCallback(JNIEnv *env, jobject instance,
                                                              jobject callback) {
    LOGD("nativeCallback");
    jclass callbackClazz = env->GetObjectClass(callback);
    jmethodID callbackMethod = env->GetMethodID(callbackClazz, "callback", "()V");
    env->CallVoidMethod(callback, callbackMethod);
}

void *threadCallback(void *) {
    //env 是不能跨线程
    JavaVM *gVM = getJvm();
    JNIEnv *env = nullptr;
    if (gVM->AttachCurrentThread(&env, nullptr) == 0) {
        env->CallVoidMethod(threadObject, threadMethod);
        gVM->DetachCurrentThread();
    }
    return JNI_OK;
}

extern "C"
JNIEXPORT void JNICALL
Java_com_jdqm_ndktutorials_jni_JNIInvokeMethod_nativeThreadCallback(JNIEnv *env,
                                                                    jobject instance,
                                                                    jobject callback) {
    //env 是不能跨线程的
    threadClazz = env->GetObjectClass(callback);
    threadMethod = env->GetMethodID(threadClazz, "callback", "()V");
    threadObject = env->NewGlobalRef(callback);
    pthread_t handle;
    pthread_create(&handle, nullptr, threadCallback, nullptr);
}