获取请求端IP地址方法

private String getIpAddr(HttpServletRequest request) {        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;    }

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