// first change ur hash map to look like this
HashMap<Integer,Integer> map = new HashMap<Integer,Integer>();

//then once your hash map has all the values calculated and shit, do this:

// make ArrayList to store modes
ArrayList<Integer> shit = new ArrayList<Integer>();

//get the iterator for all the key-value pairs
Iterator naga = map.entrySet().iterator();

int max_freq = 0;

while(naga.hasNext()){
	Map.Entry<Integer,Integer> weed = naga.next();
	int freq = weed.getValue();
	if(freq > max_freq){
		max_freq = freq;
		// clear shit array
		shit = new ArrayList<Integer>();
		shit.add(weed.getKey());
        }
	else if (freq == max_freq){
		shit.add(weed.getKey());
	}
}

//print shit array to see all the modes