Java获取ip地址

public static String getRealIpAddr(HttpServletRequest request) {
String ip = request.getHeader("X-Real-IP");
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();
}
return ip;
}