import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;


public class TestIterator {

  public static void main(String[] args) {
    Map<String,Integer> map = new LinkedHashMap<String,Integer>();
    map.put("a", 1);
    map.put("c", 3);
    map.put("b", 2);
    map.put("d", 4);

    List<Map<String,Integer>> list = getNewMapIterator(map);
    for (Map<String,Integer> m: list)
    {
      System.out.println(m);
    }
  }

  private static List<Map<String, Integer>> getNewMapIterator(
      Map<String, Integer> map) {
    List<Map<String, Integer>> maplist = new LinkedList<Map<String,Integer>>();

    if (map.size() == 1)
    {
      maplist.add(map);
      return maplist;
    }

    for (Entry<String,Integer> one : map.entrySet()){
      Map<String,Integer> others = new LinkedHashMap<String,Integer>(map);
      others.remove(one.getKey());
      List<Map<String,Integer>> lst = getNewMapIterator(others);
      for (Map<String,Integer> m: lst)
      {
        Map<String,Integer> newmap = new LinkedHashMap<String,Integer>();
        newmap.put(one.getKey(), one.getValue());
        newmap.putAll(m);
        maplist.add(newmap);
      }
    }
    return maplist;
  }
}