public static boolean isEmailValid ( String email ) { boolean isValid = false ; String expression = "^[\\w\\.-]+@([\\w\\-]+\\.)+[A-Z]{2,4}$" ; CharSequence inputStr = email ; Pattern pattern = Pattern . compile ( expression , Pattern . CASE_INSENSITIVE ); Matcher matcher = pattern . matcher ( inputStr ); if ( matcher . matches ()) { isValid = true ; } return isValid ; }