Oh lord, where to start.
You are using this to store what? A String name, and int value right.. so why is it a <String,String> and not a <String,Integer>
Why are you immediately converting the string to a int, why not just take in a int? It would save you all of these Integer calls...
You do this line 4 times, you should probably move this to a 'isValidKey' function, OR start using a enum.
You do realize this function doesn't actually return anything and thus is completely useless... right... ?
Looks to me that you want to do something more like:
public enum Stat { STRENGTH, CONSTITUTION, DEXTERITY, WILLPOWER, MIND, SPIRIT};
HashMap<Stat, Integer> stats = new HashMap<>();
public void add(Stat stat, int value) {
stats.set(stat, stats.getOrDefault(stat, 0) + value);
}