====== The Fibonacci Example ======

As a base for the illustrations presented later in this chapter, we will use a simple utility class able to calculate fibonacci numbers.


The [[http://reflex.dcc.uchile.cl/svn/base/trunk/src/reflex/examples/fibonacci/app/Fibonacci.java|code]] of the class is:

<code java>
  public class Fibonacci{

      public Fibonacci(){ }

      public long get(int n){
          if (n == 0 || n == 1){
              return (long) n;
          }

          return get(n - 1) + get(n - 2);
      }

      public static void main(String[] args){
          if (args.length == 0){
              System.out.println("Please specify which fibonacci number
              should be calculated.");
              System.exit(0);
          }

          int theN = Integer.parseInt(args[0]);

          long theFibonacciNumber = new Fibonacci().get(theN);
          System.out.println("The fibonacci[" + theN + "] is " + theFibonacciNumber);

          System.out.println();

          long theFibonacciNumberPlusOne = new Fibonacci().get(theN + 1);
          System.out.println("The fibonacci[" + (theN + 1) + "] is " +
                              theFibonacciNumberPlusOne);
      }
}
</code>

This piece of code is pretty straightforward to read: there is one empty constructor to obtain Fibonacci objects references and one unique method to calculate a fibonacci number based on the parameter that represents the one we are interested on.