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 final URL subscribeUrl;
        private final Invoker originInvoker;
        private List<Configurator> configurators;
        public OverrideListener(URL subscribeUrl, Invoker originalInvoker) {
            this.subscribeUrl = subscribeUrl;
            this.originInvoker = originalInvoker;
        }
        /**
         * @param urls The list of registered information, is always not empty, The meaning is the same as the
         *             return value of {@link org.apache.dubbo.registry.RegistryService#lookup(URL)}.
         */
        @Override
        public synchronized void notify(List<URL> urls) {
            logger.debug("original override urls: " + urls);
            List<URL> matchedUrls = getMatchedUrls(urls, subscribeUrl.addParameter(CATEGORY_KEY,
                    CONFIGURATORS_CATEGORY));
            logger.debug("subscribe url: " + subscribeUrl + ", override urls: " + matchedUrls);
            
            if (matchedUrls.isEmpty()) {
                return;
            }
            this.configurators = Configurator.toConfigurators(classifyUrls(matchedUrls, UrlUtils::isConfigurator))
                    .orElse(configurators);
            doOverrideIfNecessary();
        }
        public synchronized void doOverrideIfNecessary() {