获取客户端IP

public String getClientIP(HttpServletRequest httpservletrequest) {
     if (httpservletrequest == null)
          return null;
     String s = httpservletrequest.getHeader("X-Forwarded-For");
     if (s == null || s.length() == 0 || "unknown".equalsIgnoreCase(s))
          s = httpservletrequest.getHeader("Proxy-Client-IP");
     if (s == null || s.length() == 0 || "unknown".equalsIgnoreCase(s))
          s = httpservletrequest.getHeader("WL-Proxy-Client-IP");
     if (s == null || s.length() == 0 || "unknown".equalsIgnoreCase(s))
          s = httpservletrequest.getHeader("HTTP_CLIENT_IP");
     if (s == null || s.length() == 0 || "unknown".equalsIgnoreCase(s))
          s = httpservletrequest.getHeader("HTTP_X_FORWARDED_FOR");
     if (s == null || s.length() == 0 || "unknown".equalsIgnoreCase(s))
          s = httpservletrequest.getRemoteAddr();
     if ("127.0.0.1".equals(s) || "0:0:0:0:0:0:0:1".equals(s))
          try {
               s = InetAddress.getLocalHost().getHostAddress();
          } catch (UnknownHostException unknownhostexception) {
          }
     return s;
}