Regular Expression for determining time

The common method is to separate the hours, minutes, And seconds for determination:
Public static Boolean timecheck (string time, string owner ){
// Check whether the time string meets the format of "HH: mm: SS" or "HH: mm". If the format is not met, the system returns false.
If (time. Equals ("")){
String MSG = owner + ":" + "time is empty .";
Messagedialog. showerror (controller. getmainframe (), MSG );
Return false;
}
Int hours, minutes, seconds = 0;
Stringtokenizer ST = new stringtokenizer (time ,":");
Int tokens = ST. counttokens ();
If (tokens! = 3 & tokens! = 2 ){
String MSG = owner + ":" + "time" + time + "does not conform to the HH: mm: SS format, nor hh: Mm format .";
Messagedialog. showerror (controller. getmainframe (), MSG );
Return false;
}
String hourtoken = ST. nexttoken ();
Try {
Hours = integer. parseint (hourtoken );
} Catch (numberformatexception NFE ){
String MSG = owner + ":" + hourtoken + "in" + time + "can not be parsed as hours .";
Messagedialog. showerror (controller. getmainframe (), MSG );
Return false;
}
String minutetoken = ST. nexttoken ();
Try {
Minutes = integer. parseint (minutetoken );
} Catch (numberformatexception NFE ){
String MSG = owner + ":" + minutetoken + "in" + time + "can not be parsed as minutes .";
Messagedialog. showerror (controller. getmainframe (), MSG );
Return false;
}
If (tokens = 3 ){
String secondtoken = ST. nexttoken ();
Try {
Seconds = integer. parseint (secondtoken );
} Catch (numberformatexception NFE ){
String MSG = owner + ":" + secondtoken + "in" + time + "can not be parsed as seconds .";
Messagedialog. showerror (controller. getmainframe (), MSG );
Return false;
}
}
If (hours <0 | hours> 23 ){
String MSG = owner + ":" + "specified hours:" + hours + ". Number of hours must be in the [0 .. 23] range .";
Messagedialog. showerror (controller. getmainframe (), MSG );
Return false;
}
If (minutes <0 | minutes> 59 ){
String MSG = owner + ":" + "specified minutes:" + minutes + ". number of minutes must be in the [0 .. 59] range .";
Messagedialog. showerror (controller. getmainframe (), MSG );
Return false;
}
If (seconds <0 | seconds> 59 ){
String MSG = owner + ":" + "specified seconds:" + seconds + ". number of seconds must be in the [0 .. 59] range .";
Messagedialog. showerror (controller. getmainframe (), MSG );
Return false;
}
Return true;
}
The regular expression method is as follows:
Public static Boolean timecheck (string time, string owner ){
// Check whether the time string meets the format of "HH: mm: SS". If not, the corresponding message is displayed and false is returned.
String RegEx = "([01] \ D) | (2 [0-3]): [0-5] \ D (: [0-5] \ D )? ";
If (! Time. Matches (RegEx )){
String MSG = owner + ":" + "time is invalid .";
Messagedialog. showerror (controller. getmainframe (), MSG );
Return false;
}
Return true;
}
Very good and powerful !! However, the above regular "(2 [0-3]) | ([01] \ D): [0-5] \ D (: [0-5] \ D )?" The implementation cannot match "3: 3". It is depressing!
Change the regular expression to "(2 [0-3]) | ([0-1]? \ D): [0-5]? \ D (: [0-5]? \ D )?" It can match "", but "3: 65: 34" is obviously incorrect, but it matches two, dizzy!
Change the regular expression to "(2 [0-3]) | ([0-1]? \ D): [0-5]? \ D (: [0-5]? \ D) "can match" ", and can correctly judge" 3: 65: 34 ", but cannot judge. Alas ~~~~