springboot怎么获取用户的公网ip地址

可以通过HttpServletRequest对象获取用户的公网ip地址，代码如下：

@RequestMapping("/getIp")
public String getIp(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;
}

上面的代码中，首先尝试从请求头中获取X-Real-IP和X-Forwarded-For字段的值作为ip地址。如果这两个字段都没有，则尝试从其他请求头中获取ip地址。如果还是没有，则使用request.getRemoteAddr()方法获取ip地址。