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。
return protocol;
    }
    public void setProtocol(String protocol) {
        this.protocol = protocol;
    }
    // 
    Invoker<?> getInvoker() {
        return invoker;
    }
    @Parameter(excluded = true)
    public String getUniqueServiceName() {
        StringBuilder buf = new StringBuilder();
        if (group != null && group.length() > 0) {
            buf.append(group).append("/");
        }
        buf.append(interfaceName);
        if (StringUtils.isNotEmpty(version)) {
            buf.append(":").append(version);
        }
        return buf.toString();
    }
    @Override
    @Parameter(excluded = true)
    public String getPrefix() {
        return Constants.DUBBO + ".reference." + interfaceName;
    }
    private void resolveFile() {
        String resolve = System.getProperty(interfaceName);
        String resolveFile = null;
        if (StringUtils.isEmpty(resolve)) {