public boolean validate() {
        if (isAllIPs()) {
            return true;
        }

        List<Instance> validHosts = new ArrayList<Instance>();
        for (Instance host : hosts) {
            if (!host.isHealthy()) {
                continue;
            }

            for (int i = 0; i < host.getWeight(); i++) {
                validHosts.add(host);
            }
        }

        return true;
    }

    public List<Instance> getHosts() {
        return new ArrayList<Instance>(hosts);
    }

100. public ServiceInfo processServiceJSON(String json) {
101.         ServiceInfo serviceInfo = JSON.parseObject(json, ServiceInfo.class);
102.         ServiceInfo oldService = serviceInfoMap.get(serviceInfo.getKey());
103.         if (serviceInfo.getHosts() == null || !serviceInfo.validate()) {
104.             //empty or error push, just ignore
105.             return oldService;
106.         }
107. 
108.         if (oldService != null) {
109.             if (oldService.getLastRefTime() > serviceInfo.getLastRefTime()) {
110.                 NAMING_LOGGER.warn("out of date data received, old-t: " + oldService.getLastRefTime()
111.                     + ", new-t: " + serviceInfo.getLastRefTime());
112.             }
113. 
114.             serviceInfoMap.put(serviceInfo.getKey(), serviceInfo);
115.             //.....
116.          }
117.         //....
118. }