HttpServletRequest获取请求ip

/**
	 * 获取当前请求的IP,对使用代理后都有效
	 * @return
	 */
	public static String getRequestIP(){
		ServletRequestAttributes requestAttributes =
				(ServletRequestAttributes)RequestContextHolder.getRequestAttributes();
		HttpServletRequest request=requestAttributes.getRequest();
		String ip = request.getHeader("x-forwarded-for");
		if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getHeader("Proxy-Client-IP");
		}
		if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getHeader("WL-Proxy-Client-IP");
		}
		if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getRemoteAddr();
		}
		return ip;
	}