public int getInt(String key) {
        JsonElement value = configStorage.get(key);
        if (value == null) {
            LOGGER.error("null value for key " + key);
            throw new NullPointerException("null value for key " + key);
        }
        return value.getAsInt();
    }
get int from config

@param key key
@return value
@throws NullPointerException npe
inlong-agent/agent-common/src/main/java/org/apache/inlong/agent/conf/AbstractConfiguration.java