TimeZone validation in Java

Question

I have a string, I need to check whether it is a standard time zone identifier or not. I am not sure which method I need to use.

String timeZoneToCheck = \"UTC\"         


        

Answer 1

Since TimeZone#getTimeZone(String id) returns a default if the value is invalid (rather than returning an invalid time zone), if the reinterpreted value does not match the initial value, it wasn't valid.

private static boolean isValidTimeZone(@Nonnull String potentialTimeZone)
{
    // If the input matches the re-interpreted value, then the time zone is valid.
    return TimeZone.getTimeZone(potentialTimeZone).getID().equals(potentialTimeZone);
}