This code is based on the most voted question but I might be easier to use
public enum OS {
WINDOWS,
MAC,
LINUX,
ANDROID,
IPHONE,
UNKNOWN;
public static OS valueOf(HttpServletRequest request) {
final String userAgent = request.getHeader("User-Agent");
final OS toReturn;
if (userAgent == null || userAgent.isEmpty()) {
toReturn = UNKNOWN;
} else if (userAgent.toLowerCase().contains("windows")) {
toReturn = WINDOWS;
} else if (userAgent.toLowerCase().contains("mac")) {
toReturn = MAC;
} else if (userAgent.toLowerCase().contains("x11")) {
toReturn = LINUX;
} else if (userAgent.toLowerCase().contains("android")) {
toReturn = ANDROID;
} else if (userAgent.toLowerCase().contains("iphone")) {
toReturn = IPHONE;
} else {
toReturn = UNKNOWN;
}
return toReturn;
}
}