public synchronized void incrAllCounters(Counters other) { for (Group otherGroup: other) { Group group = getGroup(otherGroup.getName()); group.displayName = otherGroup.displayName; for (Counter otherCounter : otherGroup) { Counter counter = group.getCounterForName(otherCounter.getName()); counter.displayName = otherCounter.displayName; counter.value += otherCounter.value; } } }