2.7.0版本getContextPath方法：
```
protected String getContextPath(URL url) {
        String contextPath = url.getPath();
        return contextPath.endsWith("/") ? contextPath.substring(0,contextPath.length()-1) : contextPath;
    }
```
无法将方法置入web容器中，退回2.6.5版本的方法：
```
protected String getContextPath(URL url) {
        int pos = url.getPath().lastIndexOf("/");
        return pos > 0 ? url.getPath().substring(0, pos) : "";
    }
```
使用正常，两个方法应该不等价的。
if (INSTANCE == null) {
            ExtensionLoader.getExtensionLoader(Protocol.class).getExtension(REGISTRY_PROTOCOL); 
        }
        return INSTANCE;
    }
    
    private static String[] getFilteredKeys(URL url) {
        Map<String, String> params = url.getParameters();
        if (CollectionUtils.isNotEmptyMap(params)) {
            return params.keySet().stream()
                    .filter(k -> k.startsWith(HIDE_KEY_PREFIX))
                    .toArray(String[]::new);
        } else {
            return new String[0];
        }
    }
    public void setCluster(Cluster cluster) {
        this.cluster = cluster;
    }
    public void setProtocol(Protocol protocol) {
        this.protocol = protocol;
    }
    public void setRegistryFactory(RegistryFactory registryFactory) {
        this.registryFactory = registryFactory;
    }
    public void setProxyFactory(ProxyFactory proxyFactory) {
        this.proxyFactory = proxyFactory;
    }
    @Override
    public int getDefaultPort() {