All Major Credit Cards
This regular expression will validate all major credit cards: American Express (Amex), Discover, Mastercard, and Visa. Note that it is not quite as precise as its counterpart Perl and PHP regex.
'^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|6011[0-9]{12}|3(?:0[0-5]|[68][0-9])[0-9]{11}|3[47][0-9]{13})$'
Alpha-Numeric Characters
Test for alpha-numeric characters with this regexp.
'^[a-zA-Z0-9]+$'
Alphabetic Characters
This regex will test for alphabetic characters only (upper and lowercase).
'^[a-zA-Z]+$'
Canadian Postal Codes
Tests for valid Canadian Postal Codes.
'^[ABCEGHJKLMNPRSTVXY][0-9][A-Z] [0-9][A-Z][0-9]$'
Date (MM/DD/YYYY)
Validate the calendar date in MM/DD/YYYY format with this regex. Optional separators are spaces, hyphens, forward slashes, and periods. The year is limited between 1900 and 2099.
'^(0?[1-9]|1[012])[- /.](0?[1-9]|[12][0-9]|3[01])[- /.](19|20)?[0-9]{2}$'
Date (YYYY/MM/DD)
Validate the calendar date in YYYY/MM/DD format with this regex. Optional separators are spaces, hyphens, forward slashes, and periods. The year is limited between 1900 and 2099.
'^(19|20)?[0-9]{2}[- /.](0?[1-9]|1[012])[- /.](0?[1-9]|[12][0-9]|3[01])$'Digits
This regex will test for digits (whole numbers).
'^[0-9]+$'
Emails
This email regex is not fully RFC5322-compliant, but it will validate most common email address formats correctly.
'^[a-zA-Z0-9._%-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$'
Passwords
Test for a strong password with this regex. The password must contain one lowercase letter, one uppercase letter, one number, and be at least 6 characters long.
"(?=^.{6,}$)((?=.*[A-Za-z0-9])(?=.*[A-Z])(?=.*[a-z]))^.*"
Phone Numbers (North American)
This regex will validate a 10-digit North American telephone number. Separators are not required, but can include spaces, hyphens, or periods. Parentheses around the area code are also optional.
'^(([0-9]{1})*[- .(]*([0-9]{3})[- .)]*[0-9]{3}[- .]*[0-9]{4})+$'
URLs
This URL regex will validate most common URL formats correctly.
'^((http|https|ftp)://)?([[a-zA-Z0-9]\-\.])+(\.)([[a-zA-Z0-9]]){2,4}([[a-zA-Z0-9]/+=%&_\.~?\-]*)$'
US ZIP Codes
This regexp verifies US ZIP Codes, with an optional 4 number ZIP code extension.
'^[0-9]{5}(?:-[0-9]{4})?$'
Note : It will also work for Java only you need to remove ^ from begining and $ from last.
Reference: Java Regular Expression Tutorial with Examples
