Java如何获取HTTP请求中真实IP地址呢?

由于一些请求进行了多次转发和反向代理,那么我们如何获取这些请求的真实IP地址呢?
下文笔者将一一道来,如下所示

实现思路:
    通过获取HttpServletRequest对象中的Header头信息
	即可查找出真实的IP地址

例:
获取真实的请求IP地址

 
/**
 * 获取真实IP
 * @param request 请求体
 * @return 真实IP
 */
public static String getRealIp(HttpServletRequest request) {
	// 这个一般是Nginx反向代理设置的参数
    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.getRemoteAddr();
    }
    // 处理多IP的情况（只取第一个IP）
    if (ip != null && ip.contains(",")) {
        String[] ipArray = ip.split(",");
        ip = ipArray[0];
    }
    return ip;
}