InvocationTargetException while setting values in Java

Question

I have problem with InvocationTargetException. I am setting values of object using scanner and it became to return such strange exception for me. I did read doc and i was searching internet to find solution, but I can't figure out what's wrong. Also don't read println strings, they are in my native language.

public Person SignPerson() { 

    Scanner scanner = new Scanner(System.in);
    System.out.println("Tworzymy twoje konto użytkownika, podaj dane osobowe");
    System.out.println("Podaj swoj pesel");

    String id = setPersonalId();
    Person person = new Person(id);
    System.out.println("Podaj swoje imie");
    person.setFirstName(scanner.nextLine()); // the line taht causes problem (other 
                                                // scanners also throws exceptions)
    System.out.println("Podaj drugie imie");
    //tutaj powinien byc wgrany drugi kod do odczytu imienia
    System.out.println("Podaj nazwisko");
    person.setLastName(scanner.nextLine());
    System.out.println("Podaj nazwisko panienskie matki");
    person.setMotherMaidensName(scanner.nextLine());

    return person;
}

public static String setPersonalId() {
    String id;
    try (
            Scanner scanner2 = new Scanner(System.in);
    ) {
        id = scanner2.next();

        char[] chars = id.toCharArray();

        for (char aChar : chars) {
            if (!(aChar >= '0' && aChar <= '9'))
                throw new InvalidStringException();
        }

        return id;
    } catch (InvalidStringException e) {
        System.out.println("Wprowadziles niepoprawny pesel");
    }

    return null;
}

Please provide the full exception stacktrace – Mark Rotteveel Apr 15 '21 at 12:40 — Mark Rotteveel, Apr 15 '21 at 12:40

score 0 · Answer 1 · answered Apr 15 '21 at 12:12

0

Print e.printStackTrace() inside of Exception e block and then it points to the actual stack trace in the JDK Library. Go inside of it in the library and figure out which line is throwing error and figure out the solution based on line number in JDK Library.

answered Apr 15 '21 at 12:12

It shows something like : java.util.NoSuchElementException: no line found. The question is why there are no lines are being found? – Jakub Kołacz Apr 15 '21 at 12:24

maloomeister · Accepted Answer · 2021-04-15T12:38:25.213

There might be at least two issues here:

Don't close a Scanner wrapping System.in, as this will also close the underlying stream. (see Close a Scanner linked to System.in)

To fix this, remove the the creation of the second Scanner from the try-with-resource block, to avoid it getting closed automatically. You may also not create a second scanner, but pass the first one to the method where it will be used.
```
String id = setPersonalId(scanner);
```
and in your setPersonalId:
```
public static String setPersonalId(Scanner s) { ...
```
Calling nextLine() after calling next() will also cause problems, explained here: Scanner is skipping nextLine() after using next() or nextFoo()?:

To fix the second issue, you may simply call nextLine() everytime, instead of next() (or consume the linefeed as shown in the link):
```
id = s.nextLine();
```

InvocationTargetException while setting values in Java

2 Answers2