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。
public <T> void reExport(final Invoker<T> originInvoker, URL newInvokerUrl) {
        
        ExporterChangeableWrapper exporter = doChangeLocalExport(originInvoker, newInvokerUrl);
        
        URL registryUrl = getRegistryUrl(originInvoker);
        final URL registeredProviderUrl = getRegisteredProviderUrl(newInvokerUrl, registryUrl);
        
        ProviderInvokerWrapper<T> providerInvokerWrapper = ProviderConsumerRegTable.getProviderWrapper(registeredProviderUrl, originInvoker);
        ProviderInvokerWrapper<T> newProviderInvokerWrapper = ProviderConsumerRegTable.registerProvider(originInvoker, registryUrl, registeredProviderUrl);
        /**
         * Only if the new url going to Registry is different with the previous one should we do unregister and register.
         */
        if (providerInvokerWrapper.isReg() && !registeredProviderUrl.equals(providerInvokerWrapper.getProviderUrl())) {
            unregister(registryUrl, providerInvokerWrapper.getProviderUrl());
            register(registryUrl, registeredProviderUrl);
            newProviderInvokerWrapper.setReg(true);
        }
        exporter.setRegisterUrl(registeredProviderUrl);
    }
    /**
     * Reexport the invoker of the modified url
     *
     * @param originInvoker
     * @param newInvokerUrl
     */
    @SuppressWarnings("unchecked")
    private <T> ExporterChangeableWrapper doChangeLocalExport(final Invoker<T> originInvoker, URL newInvokerUrl) {
        String key = getCacheKey(originInvoker);
        final ExporterChangeableWrapper<T> exporter = (ExporterChangeableWrapper<T>) bounds.get(key);
        if (exporter == null) {