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。
*/
    private URL getRegisteredProviderUrl(final URL providerUrl, final URL registryUrl) {
        
        if (!registryUrl.getParameter(SIMPLIFIED_KEY, false)) {
            return providerUrl.removeParameters(getFilteredKeys(providerUrl)).removeParameters(
                    MONITOR_KEY, BIND_IP_KEY, BIND_PORT_KEY, QOS_ENABLE, QOS_PORT, ACCEPT_FOREIGN_IP, VALIDATION_KEY,
                    INTERFACES);
        } else {
            String[] paramsToRegistry = getParamsToRegistry(DEFAULT_REGISTER_PROVIDER_KEYS,
                    registryUrl.getParameter(EXTRA_KEYS_KEY, new String[0]));
            return URL.valueOf(providerUrl, paramsToRegistry, providerUrl.getParameter(METHODS_KEY, (String[]) null));
        }
    }
    private URL getSubscribedOverrideUrl(URL registeredProviderUrl) {
        return registeredProviderUrl.setProtocol(PROVIDER_PROTOCOL)
                .addParameters(CATEGORY_KEY, CONFIGURATORS_CATEGORY, CHECK_KEY, String.valueOf(false));
    }
    /**
     * Get the address of the providerUrl through the url of the invoker
     *
     * @param originInvoker
     * @return
     */
    private URL getProviderUrl(final Invoker<?> originInvoker) {
        String export = originInvoker.getUrl().getParameterAndDecoded(EXPORT_KEY);
        if (export == null || export.length() == 0) {
            throw new IllegalArgumentException("The registry export url is null! registry: " + originInvoker.getUrl());
        }
        return URL.valueOf(export);
    }