Java中使用HttpRequest获取用户真实IP地址端口

/** 
 * 获取用户真实IP地址，不使用request.getRemoteAddr();的原因是有可能用户使用了代理软件方式避免真   实IP地址, 
 *  
 * 可是，如果通过了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP值，究竟哪个才是真正的用户端的真实IP呢？ 
 * 答案是取X-Forwarded-For中第一个非unknown的有效IP字符串。 
 *  
 * 如：X-Forwarded-For：192.168.1.110, 192.168.1.120, 192.168.1.130, 
 * 192.168.1.100 
 *  
 * 用户真实IP为： 192.168.1.110 
 *  
 * @param request 
 * @return 
 */  
public static String getIpAddress(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.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;  
}