Guys,
I believe there is a pattern for this ... this should be a very common issue:
I have an object who contains an attribute with say 3 possible values, I have to do something very dramatically different in 3 cases (while loop through a bunch of instances). Now even if I have the possible attribute values stored in a lookup table I still can't avoid the following codes:
for (Iterator it = list.iterator(); it.hasNext();) {
  (MyObject)it.next();
  String attr = myObject.getMyAttr();
  if (attr.equals("CASE_A"))
   doSomethingVeryA();
  els if (attr.equals("CASE_B"))
   doSomethingVeryB();
  els if (attr.equals("CASE_C"))
   doSomethingVeryC();
}

Let's say you just can not possiblly generalize doSomethingVeryX part, how do you get rid of the "if"s? Or is that asking (trying to archtect) too much....

here we go:

public interface ObjectProcessor {
   public void processObject(Object obj);
}

public class CaseAProcessor implements ObbjectProcessor....

public class CaseBProcessor implements ObbjectProcessor....

public class CaseCProcessor implements ObbjectProcessor....

Map processors = new HashMap();
proecssors.add("case A", new CaseAPRocessor());
proecssors.add("case B", new CaseBPRocessor());
proecssors.add("case C", new CaseCPRocessor());

for (Iterator it = list.iterator(); it.hasNExt();) {
   ObjectProcessor proessor = processors.get(CASE);
   processor.processObject(it.next());
}


this code wouldn't actually compile as is, but I think you'll get the idea. the map should be initialized somewhere in a static structure, at application startup.

hope it helps.

cheers,
emil ( http://www.thekirschners.com/software/testare/testare.html ) .