public long getLongValue(String key) {
        return getLongValue(key, 0);
    }
Returns a long value of the associated keys in this {@link JSONObject}.

@param key the key whose associated value is to be returned
@return long
@throws NumberFormatException If the value of get is {@link String} and it contains no parsable long
@throws JSONException Unsupported type conversion to long value
core/src/main/java/com/alibaba/fastjson2/JSONObject.java