- [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: 2.6.5
* Operating System version: Windows 7
* Java version: 1.8.0_31

### Steps to reproduce this issue
1. API的方式配置两个registry地址，例如：        registryConfig.setAddress("127.0.0.1:2181|127.0.0.1:2182")。

2. API的方式配置ReferenceConfig按照文档配置stub，例如：       referenceConfig.setStub("com.liupeng.dubbo.api.MyStub")。

  3.API的方式启动consumer。

Pls. provide [GitHub address] to reproduce this issue.

### Expected Result

What do you expected from the above steps？

### Actual Result

What actually happens?

If there is an exception, please attach the exception trace:

```
Just put your stack trace here!
```

this.consumerUrl = consumerUrl;
        setRouters(routers);
    }
    @Override
    public List<Invoker<T>> list(Invocation invocation) throws RpcException {
        if (destroyed) {
            throw new RpcException("Directory already destroyed .url: " + getUrl());
        }
        List<Invoker<T>> invokers = doList(invocation);
        List<Router> localRouters = this.routers; 
        if (localRouters != null && !localRouters.isEmpty()) {
            for (Router router : localRouters) {
                try {
                    if (router.getUrl() == null || router.getUrl().getParameter(Constants.RUNTIME_KEY, false)) {
                        invokers = router.route(invokers, getConsumerUrl(), invocation);
                    }
                } catch (Throwable t) {
                    logger.error("Failed to execute router: " + getUrl() + ", cause: " + t.getMessage(), t);
                }
            }
        }
        return invokers;
    }
    @Override
    public URL getUrl() {
        return url;
    }
    public List<Router> getRouters() {
        return routers;
    }