JavaWeb获取客户端IP地址

1. 一种参考方式如下：

在反向代理 (Nginx) 上配置，增加 Real-IP 字段：

location / {... proxy_set_header Real-IP $remote_addr; ...}

2. 业务系统中，获取来源 IP 的代码如下(Java 示例)：

@SuppressWarnings("unchecked")
public static ClientIps getClientIpAddr(HttpServletRequest request) {
    // 获取真实 ip
    String ip = request.getHeader("real-ip");
    if (StringUtils.isBlank(ip) || ("unknown".equalsIgnoreCase(ip.trim()))) {ip = request.getHeader("remote-host");
    }
    if (StringUtils.isBlank(ip) || ("unknown".equalsIgnoreCase(ip.trim()))) {ip = request.getRemoteAddr();
    }
    ClientIps clientIps = new ClientIps();
    clientIps.setTrueIp(StringUtils.trimToEmpty(ip));
    // 获取代理 ip
    ip = request.getHeader("x-forwarded-for");
    StringBuilder proxyIps = new StringBuilder();

    if (StringUtils.isNotBlank(ip) && (StringUtils.contains(ip, ","))) {String temp = StringUtils.substringBeforeLast(ip, ",");
        if (StringUtils.isNotBlank(temp)) {proxyIps.append("x-forwarded-for:");
            proxyIps.append(temp);
            proxyIps.append("\n");
        }
    }
}