jmethodID tostr_id = env->GetMethodID(cls, "getName", "()Ljava/lang/String;");
jstring jclassname = (jstring) env->CallObjectMethod(cls, tostr_id, nullptr);
const char *classname = env->GetStringUTFChars(jclassname, 0);
jmethodID tostr_id = env->GetMethodID(cls, "getName", "()Ljava/lang/String;");
jstring jclassname = (jstring) env->CallObjectMethod(cls, tostr_id, nullptr);
const char *classname = env->GetStringUTFChars(jclassname, 0);