Question

I want to sort a Hashmap by multiple keys, at the moment i use the following code

Collections.sort(ilv2, new Comparator<HashMap<String,String>>() {
        public int compare(HashMap<String, String> arg0, HashMap<String, String> arg1) {
            // TODO Auto-generated method stub
            Time d1 = Time.valueOf(arg0.get("stamp"));
            Time d2 =Time.valueOf(arg1.get("stamp"));
            return  d1.compareTo(d2);
        }
    });

Th Hasmap ilv2 is sortet by the Time key “stamp”, but now i want to sort by the key res_id (int) and then by time, like the sql statement “order by res_id, stamp”
Any suggestions?

edit:
solution based on the given answer

Collections.sort(ilv2, new Comparator<HashMap<String,String>>() {
        public int compare(HashMap<String, String> arg0, HashMap<String, String> arg1) {
            // TODO Auto-generated method stub
            int i = 0;
            int r1 = Integer.valueOf(arg0.get("resid"));
            int r2 = Integer.valueOf(arg1.get("resid"));
            i = r1-r2;
            if(i==0){
                Time d1 = Time.valueOf(arg0.get("stamp"));
                Time d2 =Time.valueOf(arg1.get("stamp"));
                 i = d1.compareTo(d2);
            }
            return  i;
        }
    });

Answer 1

From my code, something like this:

public int compare(ProductItemData pr1, ProductItemData pr2) {
                int i = pr1.crossed.compareTo(pr2.crossed);
                if(i==0) {
                    int j = pr1.addTime.compareTo(pr2.addTime);
                    if(j==0)
                        return ((Long)pr1.id).compareTo(pr2.id);
                    else
                        return j;
                }
                return i;
            }

Read about what compareTo return.