- [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!
```

protected void setRouters(List<Router> routers) {
        
        routers = routers == null ? new ArrayList<Router>() : new ArrayList<Router>(routers);
        
        String routerKey = url.getParameter(Constants.ROUTER_KEY);
        if (routerKey != null && routerKey.length() > 0) {
            RouterFactory routerFactory = ExtensionLoader.getExtensionLoader(RouterFactory.class).getExtension(routerKey);
            routers.add(routerFactory.getRouter(url));
        }
        
        routers.add(new MockInvokersSelector());
        Collections.sort(routers);
        this.routers = routers;
    }
    public URL getConsumerUrl() {
        return consumerUrl;
    }
    public void setConsumerUrl(URL consumerUrl) {
        this.consumerUrl = consumerUrl;
    }
    public boolean isDestroyed() {
        return destroyed;
    }
    @Override
    public void destroy() {
        destroyed = true;
    }
    protected abstract List<Invoker<T>> doList(Invocation invocation) throws RpcException;
}