管理NoSuchElementException StringTokenizer

Question

I would like to manage the StringTokenizer NoSuchElementException when the username or password fields is not shown but I can not manage it.

final StringTokenizer tokenizer = new StringTokenizer(
        usernameAndPassword, ":");

System.out.println(usernameAndPassword);

while (tokenizer.hasMoreTokens()) {
    String tmp1 = tokenizer.nextToken();

    if (tokenizer.nextToken() == null) {
        System.out.println("pas d'username");
        username = "";
    } else {
        username = tmp1;
    }

    String tmp2 = tokenizer.nextToken();

    if (tokenizer.nextToken() == null) {
        System.out.println("pas de password");
        password = "";
    } else {
        password = tmp2;
    }
}

Thanks.

Answer 1

You can't just do if (tokenizer.nextToken() == null) directly before checking if it has more tokens or not.

What do you want to check using the if condition? Shouldn't it be if (StringUtils.isEmpty(tmp2)) instead of if (tokenizer.nextToken() == null) ?

If you want to scan next set of tokens then you'll have to do something like if(tokenizer.hasMoreTokens() && tokenizer.nextToken() != null) instead of just doing tokenizer.nextToken() as you don't know whether it has more tokens or not.

Answer 2

You can try adding the catch block.

try {
    final StringTokenizer tokenizer = new StringTokenizer(
            usernameAndPassword, ":");

    System.out.println(usernameAndPassword);

    while(tokenizer.hasMoreTokens()){
        String tmp1 = tokenizer.nextToken();

        if (tmp1 == null){
            System.out.println("pas d'username");
            username = "";
        }
        else{
            username = tmp1;
        }

        String tmp2 = tokenizer.nextToken();

        if (tmp2 == null){
            System.out.println("pas de password");
            password = "";
        }
        else{
            password = tmp2;
        }
    }

} catch (NoSuchElementException e) {
    password = "";
}

Answer 3

Use this instead :

final StringTokenizer tokenizer = new StringTokenizer(
        usernameAndPassword, ":");

System.out.println(usernameAndPassword);

while(tokenizer.hasMoreTokens()){
    String tmp1 = tokenizer.nextToken();

    if (tmp1 == null){
        System.out.println("pas d'username");
        username = "";
    }
    else{
        username = tmp1;
    }

    String tmp2 = tokenizer.nextToken();

    if (tmp2 == null){
        System.out.println("pas de password");
        password = "";
    }
    else{
        password = tmp2;
    }
}

When you intiliaze your string tokenizer it splits the string with the colon. So suppose you have a string A:B, it will get tokenised as A and B. You can fetch the value A and B using the nextToken() method. Whenever you call this method the pointer goes to the next element. In the above code you are using this method 4 times. After 2 time the pointer tries to fetch a value but does not succeed and hence the exception.

Thanks