class ClusterUtils {

    public static URL mergeUrl(URL remoteUrl, Map<String, String> localMap) {
        Map<String, String> map = new HashMap<String, String>();
        Map<String, String> remoteMap = remoteUrl.getParameters();

        if (remoteMap != null && remoteMap.size() > 0) {
            map.putAll(remoteMap);

            // Remove configurations from provider, some items should be affected by provider.
            map.remove(THREAD_NAME_KEY);
            map.remove(DEFAULT_KEY_PREFIX + THREAD_NAME_KEY);

            map.remove(THREADPOOL_KEY);
            map.remove(DEFAULT_KEY_PREFIX + THREADPOOL_KEY);

            map.remove(CORE_THREADS_KEY);
            map.remove(DEFAULT_KEY_PREFIX + CORE_THREADS_KEY);

            map.remove(THREADS_KEY);
            map.remove(DEFAULT_KEY_PREFIX + THREADS_KEY);

            map.remove(QUEUES_KEY);
            map.remove(DEFAULT_KEY_PREFIX + QUEUES_KEY);

            map.remove(ALIVE_KEY);
            map.remove(DEFAULT_KEY_PREFIX + ALIVE_KEY);

            map.remove(Constants.TRANSPORTER_KEY);
            map.remove(DEFAULT_KEY_PREFIX + Constants.TRANSPORTER_KEY);
        }

        if (localMap != null && localMap.size() > 0) {
            Map<String, String> copyOfLocalMap = new HashMap<>(localMap);

            if(map.containsKey(GROUP_KEY)){
                copyOfLocalMap.remove(GROUP_KEY);
            }
            if(map.containsKey(VERSION_KEY)){
                copyOfLocalMap.remove(VERSION_KEY);
            }

            copyOfLocalMap.remove(RELEASE_KEY);
            copyOfLocalMap.remove(DUBBO_VERSION_KEY);
            copyOfLocalMap.remove(METHODS_KEY);
            copyOfLocalMap.remove(TIMESTAMP_KEY);
            copyOfLocalMap.remove(TAG_KEY);

            map.putAll(copyOfLocalMap);

            map.put(REMOTE_APPLICATION_KEY, remoteMap.get(APPLICATION_KEY));

            // Combine filters and listeners on Provider and Consumer
            String remoteFilter = remoteMap.get(REFERENCE_FILTER_KEY);
            String localFilter = copyOfLocalMap.get(REFERENCE_FILTER_KEY);
            if (remoteFilter != null && remoteFilter.length() > 0
                    && localFilter != null && localFilter.length() > 0) {
                map.put(REFERENCE_FILTER_KEY, remoteFilter + "," + localFilter);
            }
            String remoteListener = remoteMap.get(INVOKER_LISTENER_KEY);
            String localListener = copyOfLocalMap.get(INVOKER_LISTENER_KEY);
            if (remoteListener != null && remoteListener.length() > 0
                    && localListener != null && localListener.length() > 0) {
                map.put(INVOKER_LISTENER_KEY, remoteListener + "," + localListener);
            }
        }

        return remoteUrl.clearParameters().addParameters(map);
    }

    private  ClusterUtils();

}