java获取客户端ip地址

/**
	 * 获取用户真实IP地址，不使用request.getRemoteAddr();的原因是有可能用户使用了代理软件方式避免真实IP地址,
	 * 
	 * 可是，如果通过了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP值，究竟哪个才是真正的用户端的真实IP呢？
	 * 答案是取X-Forwarded-For中第一个非unknown的有效IP字符串。
	 * 
	 * 如：X-Forwarded-For：192.168.1.110, 192.168.1.120, 192.168.1.130,192.168.1.100
	 * 
	 * 用户真实IP为： 192.168.1.110 
	 * -----------------------------------
	 * 同一个路由下wifi的多个用户被判定为一个ip
	 * 
	 *
	 */


	public static String getIpAddress(HttpServletRequest request) {
		String ip = request.getHeader("X-Real-IP");
		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
			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.getHeader("HTTP_CLIENT_IP");
		}
		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getHeader("HTTP_X_FORWARDED_FOR");
		}
		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getRemoteAddr();
		}
		return ip;
	}