com_example_yourapp_CvUtil.cpp

// Find the class of Float
jclass FloatClass = env->FindClass(“java/lang/Float”);
// And the method ID of constructor of the Float class
jmethodID FloatInit = env->GetMethodID(FloatClass, “<init>”, “(F)V”);
for (int i = 0; i < 10; i += 1) {
    jsize index = i;
    // Create instances of Float
    jobject value1 = env->NewObject(FloatClass, FloatInit, xxx);
    jobject value2 = env->NewObject(FloatClass, FloatInit, xxx);
    // Put the Float values into float arrays
    env->SetObjectArrayElement(array1, index, value1);
    env->SetObjectArrayElement(array2, index, value2);
}

// Now let’s put the float arrays into the ArrayList
jmethodID addElementMethod = env->GetMethodID(arrayListClass, “add”, “(Ljava/lang/Object;)Z”);
env->CallBooleanMethod(arrayList, addElementMethod, array1);
env->CallBooleanMethod(arrayList, addElementMethod, array2);

return arrayList;