Examples with Exporter com.alibaba.dubbo.rpc.Exporter used on opensource projects

Example 1 with Exporter

use of com.alibaba.dubbo.rpc.Exporter in project dubbo by alibaba.

the class RegistryProtocol method export.

public <T> Exporter<T> export(final Invoker<T> originInvoker) throws RpcException {
    //export invoker
    final ExporterChangeableWrapper<T> exporter = doLocalExport(originInvoker);
    //registry provider
    final Registry registry = getRegistry(originInvoker);
    final URL registedProviderUrl = getRegistedProviderUrl(originInvoker);
    registry.register(registedProviderUrl);
    // 订阅override数据
    // FIXME 提供者订阅时，会影响同一JVM即暴露服务，又引用同一服务的的场景，因为subscribed以服务名为缓存的key，导致订阅信息覆盖。
    final URL overrideSubscribeUrl = getSubscribedOverrideUrl(registedProviderUrl);
    final OverrideListener overrideSubscribeListener = new OverrideListener(overrideSubscribeUrl);
    overrideListeners.put(overrideSubscribeUrl, overrideSubscribeListener);
    registry.subscribe(overrideSubscribeUrl, overrideSubscribeListener);
    //保证每次export都返回一个新的exporter实例
    return new Exporter<T>() {

        public Invoker<T> getInvoker() {
            return exporter.getInvoker();
        }

        public void unexport() {
            try {
                exporter.unexport();
            } catch (Throwable t) {
                logger.warn(t.getMessage(), t);
            }
            try {
                registry.unregister(registedProviderUrl);
            } catch (Throwable t) {
                logger.warn(t.getMessage(), t);
            }
            try {
                overrideListeners.remove(overrideSubscribeUrl);
                registry.unsubscribe(overrideSubscribeUrl, overrideSubscribeListener);
            } catch (Throwable t) {
                logger.warn(t.getMessage(), t);
            }
        }
    };
}

Example 2 with Exporter

use of com.alibaba.dubbo.rpc.Exporter in project dubbo by alibaba.

the class CallbackServiceCodec method exportOrunexportCallbackService.

/**
     * client 端export callback service
     * @param channel
     * @param clazz
     * @param inst
     * @param export
     * @param out
     * @throws IOException
     */
@SuppressWarnings({ "unchecked", "rawtypes" })
private static String exportOrunexportCallbackService(Channel channel, URL url, Class clazz, Object inst, Boolean export) throws IOException {
    int instid = System.identityHashCode(inst);
    Map<String, String> params = new HashMap<String, String>(3);
    //不需要在重新new client
    params.put(Constants.IS_SERVER_KEY, Boolean.FALSE.toString());
    //标识callback 变于排查问题
    params.put(Constants.IS_CALLBACK_SERVICE, Boolean.TRUE.toString());
    String group = url.getParameter(Constants.GROUP_KEY);
    if (group != null && group.length() > 0) {
        params.put(Constants.GROUP_KEY, group);
    }
    //增加方法，变于方法检查，自动降级(见dubbo protocol)
    params.put(Constants.METHODS_KEY, StringUtils.join(Wrapper.getWrapper(clazz).getDeclaredMethodNames(), ","));
    Map<String, String> tmpmap = new HashMap<String, String>(url.getParameters());
    tmpmap.putAll(params);
    //callback不需要区分version
    tmpmap.remove(Constants.VERSION_KEY);
    tmpmap.put(Constants.INTERFACE_KEY, clazz.getName());
    URL exporturl = new URL(DubboProtocol.NAME, channel.getLocalAddress().getAddress().getHostAddress(), channel.getLocalAddress().getPort(), clazz.getName() + "." + instid, tmpmap);
    //同一个jvm不需要对不同的channel产生多个exporter cache key不会碰撞 
    String cacheKey = getClientSideCallbackServiceCacheKey(instid);
    String countkey = getClientSideCountKey(clazz.getName());
    if (export) {
        //同一个channel 可以有多个callback instance. 不同的instance不重新export
        if (!channel.hasAttribute(cacheKey)) {
            if (!isInstancesOverLimit(channel, url, clazz.getName(), instid, false)) {
                Invoker<?> invoker = proxyFactory.getInvoker(inst, clazz, exporturl);
                //资源销毁？
                Exporter<?> exporter = protocol.export(invoker);
                //这个用来记录instid是否发布过服务
                channel.setAttribute(cacheKey, exporter);
                logger.info("export a callback service :" + exporturl + ", on " + channel + ", url is: " + url);
                increaseInstanceCount(channel, countkey);
            }
        }
    } else {
        if (channel.hasAttribute(cacheKey)) {
            Exporter<?> exporter = (Exporter<?>) channel.getAttribute(cacheKey);
            exporter.unexport();
            channel.removeAttribute(cacheKey);
            decreaseInstanceCount(channel, countkey);
        }
    }
    return String.valueOf(instid);
}