smiley-http-proxy-servlet 反向代理时丢失cookie的问题

在使用smiley-http-proxy-servlet实现反向代理时，发现在进行转发时原始request中的cookie信息丢失了。翻看了其源代码后发现在ProxyServlet进行http转发时是有copy原始request中的header（包括cookie）的操作的，如下：

 /** Copy request headers from the servlet client to the proxy request. */
  protected void copyRequestHeaders(HttpServletRequest servletRequest, HttpRequest proxyRequest) {
    // Get an Enumeration of all of the header names sent by the client
    Enumeration enumerationOfHeaderNames = servletRequest.getHeaderNames();
    while (enumerationOfHeaderNames.hasMoreElements()) {
      String headerName = (String) enumerationOfHeaderNames.nextElement();
      //Instead the content-length is effectively set via InputStreamEntity
      if (headerName.equalsIgnoreCase(HttpHeaders.CONTENT_LENGTH))
        continue;
      if (hopByHopHeaders.containsHeader(headerName))
        continue;

      Enumeration headers = servletRequest.getHeaders(headerName);
      while (headers.hasMoreElements()) {//sometimes more than one value
        String headerValue = (String) headers.nextElement();
        // In case the proxy host is running multiple virtual servers,
        // rewrite the Host header to ensure that we get content from
        // the correct virtual server
        if (headerName.equalsIgnoreCase(HttpHeaders.HOST)) {
          HttpHost host = getTargetHost(servletRequest);
          headerValue = host.getHostName();
          if (host.getPort() != -1)
            headerValue += ":"+host.getPort();
            // 就是下面这句copy了cookie
        } else if (headerName.equalsIgnoreCase(org.apache.http.cookie.SM.COOKIE)) {
          headerValue = getRealCookie(headerValue);
        }
        proxyRequest.addHeader(headerName, headerValue);
      }
    }
  }

 

但是在进行copy时做了限定——只copy name为特定前缀的cookie，该方法代码如下：

/** The string prefixing rewritten cookies. */
  protected String getCookieNamePrefix() {
    return "!Proxy!" + getServletConfig().getServletName();
  }

 而原始的cookie均不是该前缀，因此出现了cookie丢失的问题。找到问题原因之后，要修改就容易了很多。要么将原始cookie name追加相应的前缀，要么实现一个URITemplateProxyServlet的子类，覆写getCookieNamePrefix方法即可。