Regular expression: user input validation checks

Validate email properties:

String regexExp = "^[a-zA-Z0-9]+[.a-zA-Z0-9_-]+@[a-zA-Z0_.-]+\\.[a-zA-Z]+$";

String regexExp2 = "^[a-zA-Z]+@[a-zA-Z0_.-]+\\.[a-zA-Z]+$";

String errMessage = "Invalid email address.";

Validate alpha numeric properties:

String regexExp = "[a-zA-z0-9]*";

Validate numeric properties:

String regexExp = "^[-+]?\\d*\\.?\\d*$";

Validate alpha properties:

String regexExp = "^([a-zA-Z\\s-\']+)$";

Validate URL properties:

String regexExp = "(HTTPS?://)[A-Z0-9.-]+\\.[A-Z]{2,6}([\\w\\d:#@%/;$()~_?\\+\\-=\\\\\\.&]*)";

String