[SalesForce] Apex regex pattern to match Space hyphen Integer

Ultimately, the code I came up with for validation looked something like what's below:

list<Event> ToInsert = new list<Event>();
Date ClosDt;
Integer ClsDay; 
Integer ClsMnth;
Integer ClsYear; 
String sClsDay; 
String sClsMnth;
String sClsYear; 
String StrtTmDt;
Integer plnMns;
String endTm;
String endDtTm;
String notes;
Pattern TimePttrn = Pattern.compile('((([1])([0-2])|(([0])([1-9])))(\\u003A)(([0-5])([0-9]))(\\s)(([AP])([M])))'); // hh:mm a


// The initial section below is to use Event_Notes__c to track any error messages 
// related to the start time and return them for correction while allowing 
// successful creation of the event. It existed before we went to a picklist.

try{
    If (opp.Event_Notes__c == null) notes = 'None';

    }catch(NullPointerException e){

    notes = 'None';

    } 

    notes = opp.Event_Notes__c;

try{
    opp.Event_Start_Time_Pik__c.normalizeSpace();

    }catch(NullPointerException e){

        if (notes == 'None') {

            notes = 'Error A1 processing Start Time!!! Check for correct time and resubmit form.';

            opp.Event_Start_Time_Pik__c = '12:00 AM';

        } else{

            notes = 'Error A2 processing Start Time!!! Check for correct time and resubmit form.'+ notes;

            opp.Event_Start_Time_Pik__c = '12:00 AM'; 

        }

    } // End try/catch block

// Do time pattern and match validation

Matcher m = TimePttrn.matcher(opp.Event_Start_Time_Pik__c);
boolean hasMatch = m.matches();
strtTm = m.group(0);

opp.Event_Notes__c = notes;

// Assemble StartTimeDate and Calculate Planned Mins

ClosDt = opp.CloseDate;
ClsDay = ClosDt.day();

if(ClsDay >= 1 && ClsDay <= 9){ 

sClsDay = '0' + String.ValueOf(ClsDay);

} else {

sClsDay = String.ValueOf(ClsDay);

}

ClsMnth = ClosDt.month();

if(ClsMnth >=0 && ClsMnth <= 9){ 

   sClsMnth = '0' + String.ValueOf(ClsMnth);

   } else {

   sClsMnth = String.ValueOf(ClsMnth);

   }

ClsYear = ClosDt.year();

sClsYear = String.ValueOf(ClsYear);    

StrtTmDt = sClsMnth + '/' + sClsDay + '/' + sClsYear + ' ' + strtTm;

Later in the code when creating the event:

Event e = New Event(StartDateTime = DateTime.parse(StrtTmDt), ActivityDateTime = DateTime.parse(StrtTmDt), EndDateTime = (DateTime.parse(StrtTmDt)).addMinutes(plnMns), DurationInMinutes = plnMns, Subject = EvtSubjct, OwnerId = opp.Owner.Id, WhatId = opp.Id, WhoId = opp.Customer_Contact__r.Id, Description = Descr1 + Descr2 + Descr3 + Descr5 + Descr6 + Descr7 );

I wound up doing a lot of string method and regex testing bits of code in the Developer Console and creating some string test classes before I managed to get all of this to work satisfactorily. I learned a great deal in the process. I hope others find this of use as until there's a "true" Time method other than the Salesforce System Time, this will continue to be an issue we'll all need to deal with on occasion.

Found the issue. It was not with the Regex pattern but with the Apex code.

 String strRegEx = '\\bhot\\b';
 String str = ' how hot is it';

 Pattern MyPattern = Pattern.compile(strRegEx);
 Matcher MyMatcher = MyPattern.matcher(str);
 Boolean result = MyMatcher.find();