Struts2中action获取客户端IP

HttpServletRequest req=(HttpServletRequest)ServletActionContext.getRequest();
        String lastLoginIP = req.getHeader("x-forwarded-for");  
        if(lastLoginIP == null || lastLoginIP.length() == 0 || "unknown".equalsIgnoreCase(lastLoginIP)) {  
            lastLoginIP = req.getHeader("Proxy-Client-IP");  
        }  
        if(lastLoginIP == null || lastLoginIP.length() == 0 || "unknown".equalsIgnoreCase(lastLoginIP)) {  
            lastLoginIP = req.getHeader("WL-Proxy-Client-IP");  
        }  
        if(lastLoginIP == null || lastLoginIP.length() == 0 || "unknown".equalsIgnoreCase(lastLoginIP)) {  
            lastLoginIP = req.getRemoteAddr();  
        }