定时拉取注册表

/**
 * 服务注册中心客户端缓存
 */
public class ClientCachedServiceRegistry {
    //服务注册表拉取间隔时间
    private static final Long SERVICE_REGISTRY_FETCH_INTERVAL = 30 * 1000L;
    //拉取注册表的后台线程
    private Daemon daemon;
    //客户端缓存注册表
    private Map<String, Map<String, ServiceInstance>> registry =
            new HashMap<String, Map<String, ServiceInstance>>();
    //客户端引用
    private RegisterClient registerClient;
    //通信组件
    private HttpSender httpSender;
    public ClientCachedServiceRegistry(RegisterClient registerClient,HttpSender httpSender) {
        this.daemon = new Daemon();
        this.registerClient = registerClient;
        this.httpSender = httpSender;
    }
    /**
     * 启动后台线程
     */
    public void initialize() {
        daemon.start();
    }
    /**
     * 销毁后台线程
     */
    public void destory() {
        this.daemon.interrupt();
    }
    /**
     * 负责定时拉取注册表信息
     */
    private class Daemon extends Thread {
        @Override
        public void run() {
            //当客户端存活的时候继续循环，没有存活时就不能继续循环了
            while (registerClient.isRunning()) {
                try {
                    //通过通信组件获取服务注册表
                    registry = httpSender.fetchServiceRegistry();
                    Thread.sleep(SERVICE_REGISTRY_FETCH_INTERVAL);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}