Breaking out of a recursion in java

Question

The recursion is sort of a \'divide and conquer\' style, it splits up while getting smaller (Tree data structure), and I want it to break completely if a violation is found,

Answer 1

I'd recommend an exception handling. That makes clear, that the recursion was aborted because of some violation (or other exception):

public void outer() {
  try {
    int i = recurse(0);
  } catch (OuchException ouch) {
    // handle the exception here
  }
}

private int recurse(int i) throws OuchException {

    // for tree-like structures
    if (thisIsALeaf) {
       return i;
    }

    // the violation test
    if (itHurts)
       throw new OuchException("That really hurts");

    // we also can encapsulate other exceptions
    try {
       someMethod();
    } catch (Exception oops) {
       throw new OuchException(oops);
    }

    // recurse
    return recurse(i++);
}

Sure, it violates the initial requirement to return 'true' upon abortion. But I prefer a clean separation of return values and notification on abnormal behaviour.