Java appending unexpectedly

Question

I'm trying to run a check whether or not a user has entered the @gmail.com suffix to their input. If not, then append it. I'm having a little difficulty because this loop seems to be written correctly to me. I'm at a loss. Anyone? I'm sure it's simple, I just can't see it.

String UN;
Scanner sc = new Scanner(System.in);
String suf = "@gmail.com";
boolean sufd;
// your code goes here
UN = sc.nextLine(); //
if(UN.length() >= 11){
    sufd = UN.substring(UN.length()-11,UN.length()-1).equals("@gmail.com");
    if(!sufd) {
        UN += suf;
    }
} else if(UN.length() < 11) {
    UN += suf;
}
System.out.print(UN);

That's mighty complex. Why don't you use [String.endsWidth](http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#endsWith%28java.lang.String%29)? — Kenney, Dec 12 '15 at 17:42
Call me an idiot, but I didn't know that method existed. Thank you. — Phil C., Dec 12 '15 at 17:43

score 2 · Accepted Answer · answered Dec 12 '15 at 18:13

Using the official java email package is the easiest:

public static boolean isValidEmailAddress(String email) {
   boolean result = true;
   try {
      InternetAddress emailAddr = new InternetAddress(email);
      emailAddr.validate();
   } catch (AddressException ex) {
      result = false;
   }
   return result;
}

score 1 · Answer 2 · answered Dec 12 '15 at 18:17

    public boolean isValidEmailAddress(String email) {
           String ePattern = "^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@((\\[[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\])|(([a-zA-Z\\-0-9]+\\.)+[a-zA-Z]{2,}))$";
           java.util.regex.Pattern p = java.util.regex.Pattern.compile(ePattern);
           java.util.regex.Matcher m = p.matcher(email);
           return m.matches();
    }

Test Cases:

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Java appending unexpectedly

2 Answers2