- [x] I have searched the [issues](https://github.com/apache/incubator-dubbo/issues) of this repository and believe that this is not a duplicate.
- [x] I have checked the [FAQ](https://github.com/apache/incubator-dubbo/blob/master/FAQ.md) of this repository and believe that this is not a duplicate.

### Environment

* Dubbo version: 2.6.4

### Steps to reproduce this issue

1. GenericService泛化调用
2. 使用oninvoke、onreturn、onthrow
3. FutureFilter无法正常回调

### Expected Result
StaticContext.getKey(invoker.getUrl(), invocation.getMethodName(), Constants.ON_INVOKE_METHOD_KEY)
返回
com.alibaba.boot.dubbo.demo.consumer.DemoService:1.0.0.sayHello.oninvoke.method

### Actual Result
StaticContext.getKey(invoker.getUrl(), invocation.getMethodName(), Constants.ON_INVOKE_METHOD_KEY)
返回
com.alibaba.boot.dubbo.demo.consumer.DemoService:1.0.0.$invoke.oninvoke.method

预期是：

```
        String methodName = invocation.getMethodName();
        if("$invoke".equals(methodName)) {
            Object[] arguments = invocation.getArguments();
            methodName = (String) arguments[0];
        }
```

for (URL u : us) {
                        URL monitorUrl = loadMonitor(u);
                        if (monitorUrl != null) {
                            map.put(Constants.MONITOR_KEY, URL.encode(monitorUrl.toFullString()));
                        }
                        urls.add(u.addParameterAndEncoded(Constants.REFER_KEY, StringUtils.toQueryString(map)));
                    }
                }
                if (urls.isEmpty()) {
                    throw new IllegalStateException("No such any registry to reference " + interfaceName + " on the consumer " + NetUtils.getLocalHost() + " use dubbo version " + Version.getVersion() + ", please config <dubbo:registry address=\"...\" /> to your spring config.");
                }
            }
            if (urls.size() == 1) {
                invoker = refprotocol.refer(interfaceClass, urls.get(0));
            } else {
                List<Invoker<?>> invokers = new ArrayList<Invoker<?>>();
                URL registryURL = null;
                for (URL url : urls) {
                    invokers.add(refprotocol.refer(interfaceClass, url));
                    if (Constants.REGISTRY_PROTOCOL.equals(url.getProtocol())) {
                        registryURL = url; // 
                    }
                }
                if (registryURL != null) { // 
                    // 
                    URL u = registryURL.addParameter(Constants.CLUSTER_KEY, RegistryAwareCluster.NAME);
                    // 
                    invoker = cluster.join(new StaticDirectory(u, invokers));
                } else { // 
                    invoker = cluster.join(new StaticDirectory(invokers));