com.alibaba.dubbo.governance.web.governance.module.screen.Providers#getServiceAppMap 
at line 133 ， should be providers.size > 0 or just delete this comparison cause the next for will skip if proviers.size == 0
for (Provider provider : providers) {
                Set<String> appSet;
                String service = provider.getService();
                if (serviceAppMap.get(service) == null) {
                    appSet = new HashSet<String>();
                } else {
                    appSet = serviceAppMap.get(service);
                }
                appSet.add(provider.getApplication());
                serviceAppMap.put(service, appSet);
            }
        }
        return serviceAppMap;
    }
    /**
     * Record search history to cookies, steps:
     * Check whether the added record exists in the cookie, and if so, update the list order; if it does not exist, insert it to the front
     *
     * @param context
     * @param value
     */
    private void setSearchHistroy(Map<String, Object> context, String value) {
        
        String separatorsB = "\\.\\.\\.\\.\\.\\.";
        String newCookiev = value;
        Cookie[] cookies = request.getCookies();
        for (Cookie c : cookies) {
            if (c.getName().equals("HISTORY")) {
                String cookiev = c.getValue();
                String[] values = cookiev.split(separatorsB);