private Map<List<String>, Integer> cropCache;
        private Map<Person, Map<List<String>, Integer>> unitCache;

Map<List<String>,Integer> cropCache = new HashMap<List<String>,Integer>();
         Map<List<String>, Map<List<String>,Integer> > unitCache = new HashMap ....

List<String> strList = new ArrayList<String>(5);

    strList.add("A");
    strList.add("B");
    strList.add("C");
    strList.add("D");
    strList.add("E");

int[] intArr = { 5, 3, 2, 4, 4};

List<Integer> intList = new ArrayList<Integer>();
    for (int index = 0; index < intArr.length; index++)
    {
        intList.add(intArr[index]);
    }

for (Integer number : intList)
        for (String str : strList)
                cropCache.put(str, intList);