Java获取客户端请求IP地址

// 获得IP地址
public static String getIpAddr(HttpServletRequest request) {
    String ipAddress = null;
    ipAddress = request.getHeader("x-forwarded-for");
    if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
        ipAddress = request.getHeader("Proxy-Client-IP");
    }
    if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
        ipAddress = request.getHeader("WL-Proxy-Client-IP");
    }
    if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
        ipAddress = request.getRemoteAddr();
        if (ipAddress.equals("127.0.0.1")) {
            // 根据网卡取本机配置的IP
            InetAddress inet = null;
            try {
                inet = InetAddress.getLocalHost();
            } catch(UnknownHostException e) {
                e.printStackTrace();
            }
            ipAddress = inet.getHostAddress();
        }
 
    }
 
    // 对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
    if (ipAddress != null && ipAddress.length() > 15) { // "***.***.***.***".length()
        // = 15
        if (ipAddress.indexOf(",") > 0) {
            ipAddress = ipAddress.substring(0, ipAddress.indexOf(","));
        }
    }
    return ipAddress;
}