//檢查Email格式是否合法
String check = "^([a-z0-9A-Z]+[-|\\.]?)+[a-z0-9A-Z]@([a-z0-9A-Z]+(-[a-z0-9A-Z]+)?\\.)+[a-zA-Z]{2,}$";
Pattern regex = Pattern.compile(check);
Matcher matcher = regex.matcher(email);
boolean isMatched = matcher.matches();
if(!isMatched){
return "請輸入正確的郵箱格式";
}