How to Get Client IP Address in Java

/*Source:
https://stackoverflow.com/a/21529994/3599237
*/
public static String getClientIpAddr(HttpServletRequest request) {  
    String ip = request.getHeader("X-Forwarded-For");  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("Proxy-Client-IP");  
    }  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("WL-Proxy-Client-IP");  
    }  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("HTTP_X_FORWARDED_FOR");  
    }  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("HTTP_X_FORWARDED");  
    }  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("HTTP_X_CLUSTER_CLIENT_IP");  
    }  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("HTTP_CLIENT_IP");  
    }  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("HTTP_FORWARDED_FOR");  
    }  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("HTTP_FORWARDED");  
    }  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("HTTP_VIA");  
    }  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("REMOTE_ADDR");  
    }  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getRemoteAddr();  
    }  
    return ip;  
}
/*
https://memorynotfound.com/client-ip-address-java/
*/
private static final String[] IP_HEADER_CANDIDATES = { 
    "X-Forwarded-For",
    "Proxy-Client-IP",
    "WL-Proxy-Client-IP",
    "HTTP_X_FORWARDED_FOR",
    "HTTP_X_FORWARDED",
    "HTTP_X_CLUSTER_CLIENT_IP",
    "HTTP_CLIENT_IP",
    "HTTP_FORWARDED_FOR",
    "HTTP_FORWARDED",
    "HTTP_VIA",
    "REMOTE_ADDR" };

public static String getClientIpAddress(HttpServletRequest request) {
    for (String header : IP_HEADER_CANDIDATES) {
        String ip = request.getHeader(header);
        if (ip != null && ip.length() != 0 && !"unknown".equalsIgnoreCase(ip)) {
            return ip;
        }
    }
    return request.getRemoteAddr();
}