import java.util.*;
import java.lang.*;
class HashMapSorter
{
 public static void main(String arg[])
 {
   HashMap<String,Integer> mapproduct = new HashMap();
   mapproduct.put("1",2);mapproduct.put("2",1);
   System.out.println("Before Sorting:"+mapproduct);
Map<String, Integer> sorted = sortByKeys(mapproduct);
   System.out.println("After Sorting :"+sorted);
 }
public static <K extends Comparable,V extends Comparable> Map<K,V> sortByKeys(Map<K,V> map){
        List<K> keys = new LinkedList<K>(map.keySet());
        Collections.sort(keys);

        //LinkedHashMap will keep the keys in the order they are inserted
        //which is currently sorted on natural ordering
        Map<K,V> sortedMap = new LinkedHashMap<K,V>();
        for(K key: keys){
            sortedMap.put(key, map.get(key));
        }

        return sortedMap;
    }

}