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。
/**
     * A {@link ProxyFactory} implementation that will generate a reference service's proxy,the JavassistProxyFactory is
     * its default implementation
     */
    private static final ProxyFactory proxyFactory = ExtensionLoader.getExtensionLoader(ProxyFactory.class).getAdaptiveExtension();
    /**
     * The url of the reference service
     */
    private final List<URL> urls = new ArrayList<URL>();
    /**
     * The interface name of the reference service
     */
    private String interfaceName;
    /**
     * The interface class of the reference service
     */
    private Class<?> interfaceClass;
    /**
     * client type
     */
    private String client;
    /**
     * The url for peer-to-peer invocation
     */
    private String url;
    /**
     * The method configs
     */
    private List<MethodConfig> methods;
    /**