Really really really really want to modify objects in an iterator call

Question

Hey,
I know you are not really allowed to do this, but I am iterating over some objects and I want to modify them while iterating over them without getting a ConcurrentModificationException.
Collection collection = myHashMap.values();
for (Iterator iter = collection .iterator(); iter.hasNext())
MyObject obj = (MyObject) iter.next();
modifySomethingWithinMyObject(obj);
not only does modifySomethingWithinMyObject(obj) modify the object being passed in but it also may modify other values within the hashmap.
This is really killing me. anyone know how to get around this?

Answer 1

I know you are not really allowed to do this, but I am
iterating over some objects and I want to modify them
while iterating over them without getting a
ConcurrentModificationException.If you're using HashMap in a concurrent situation you should synchronize it. That takes care of the ConcurrentModificationException.
You're not allowed to modify the HashMap structure while iterating through it (other than by using the metods available in the Iterator itself). If you do you may get something like a BadStructureException or so.
You can modify the objects stored in the HashMap as long as you don't modify anything used by the equals or hashCode methods (if you've overridden them), but in a concurrent situation you should synchronize all object methods that modifies the objects content.