First, in order to get an objective comparison of code length you should at least use the same (length) variable names. You used "lineTokenizer" in your Java example and "l" in your Ruby example!

Second, you could have just written System.out.println(sum) in Java. The fact that you had to write System.out.println(Integer.toString(sum)) shows your lack of basic Java knowledge.

Lastly, the brackets around your one-line while loop in Java are unnecessary, unlike the brackets around your closure in Ruby.

Also, the Java main method declaration is irrelevant to your point, since it's written only once per program, and is automatically created by any IDE.

How about this equivalent Java code to match your Ruby example:

  int count = 0;
  Scanner s = new Scanner(System.in);
  while (s.hasNextInt())
    count += s.nextInt();
  System.out.println(count);