Infinite loop on Scanner.hasNext, reading from a file

Question

I\'m apparently facing an infinite loop on while(input.hasNext()) , as in following code

File file = new File(\"data.txt\");
Scanner input = new Sca         


        

Answer 1

Well, according to

while(input.hasNext()) {
  if(input.hasNextInt()) {
    sum += input.nextInt();
  }
}

Your scanner will not consume the next token if this token isn't an int, you can hilight this behavior with something like

int k=0;
while(input.hasNext()) {
  if(input.hasNextInt()) {
    sum += input.nextInt();
  } else {
    System.err.println("What ? It's not an integer...");
    if ( k < 1 ) {
      System.err.println("I'm gonna try again !");
      k++;
    } else {
      System.err.println("'"+input.next()+"' it's definitively not an integer");
      k=0;
    }
  }
}

Finally, there are many solutions, for example :

• Modify your input file the remove all the non-integer token
• Consume the non-integer token with Scanner::next()
• Sanjeev's answer