How to sor hash map

Question

Hi,
[b] how to sort hash map contains integer objects,
HashMap map=new HashMap();
map.put("1",new Integer("1"));
map.put("2",new Ineger("2")):
map.put("3",new Ineger("3")):
map.put(4,new Integer("4"));
map.put("10",new Integer("10"));
map.put("11",new Integer("11"));
map.put("12",new Integer("12"));
map.put("20",new Integer("20"));
map.put(30,new Integer("30"));
if i am using treemap
TreeMap map1=new TreeMap(map);
System.out.println(map1);
answer is
1 ,10,11,12,2,20,3,30,4
but i am accepting the results
1,2,3,4,10,11,12,20,30.
what to do
with regardsshannu sarma[/b]

Answer 1

This is usual behaviour of a Map. You cannot sort a Set or Map. You can sort a List only using Collections.sort().
If you want to use a Map which adds all elements according to the order you've added it, then use LinkedHashMap.
And if you want to capture the keys, use Map.values() which returns an ordered Collection (and after converting it to List, you can sort it).
Another approach is to create a wrapper object and put it in a List. Then you can use the java.util.Comparator to sort objects in a List.