check valid email address in Java.

//Initialize reg ex for email.
String expression = "^[\\w\\.-]+@([\\w\\-]+\\.)+[A-Z]{2,4}$";
CharSequence inputStr = email;
//Make the comparison case-insensitive.
Pattern pattern = Pattern.compile(expression,Pattern.CASE_INSENSITIVE);
Matcher matcher = pattern.matcher(inputStr);
if(matcher.matches()){
isValid = true;
}
return isValid;
}