Using try(Scanner scan = new Scanner(System.in)) { }
is causing
Exception in thread "main" java.util.NoSuchElementException
When I try to debug it says that
Variable information not available, source compiled without -g option.
and shows the below code
public Scanner(InputStream source) {
this(new InputStreamReader(source), WHITESPACE_PATTERN);
}
One of my methods that uses this line:
protected String loginName(){
String username;
String password;
try (Scanner scan = new Scanner(System.in)) { // This line is causing the error.
System.out.print("Enter Username: ");
username = scan.next();
System.out.print("Enter Password: ");
password = scan.next();
}
if(getUsernamesList().contains(username))
if(password.equals(getPasswordsList().get(getUsernamesList().indexOf(username)))) return username;
else return "-1";
else return "-1";
}
You're closing System.in
(a global-variable). Please , do not do that. Everywhere you have
try(Scanner scan = new Scanner(System.in))
guarantees that System.in
will be close
(d). Once it's close
(d) you can't read from it again (or you get your mentioned Exception
). Also, you can compile with debug symbols (or step into it with your IDE's built-in debugger or jdb as applicable). The Scanner.close()
Javadoc says (in part),
If this scanner has not yet been closed then if its underlying readable also implements the
Closeable
interface then the readable'sclose
method will be invoked
Have you tried not using the try?
String username;
String password;
Scanner scan = new Scanner(System.in);
System.out.print("Enter Username: ");
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