public static void main(String[] args) {        Map
     
       map = new TreeMap
      
       ();        map.put("d", "ddddd");        map.put("c", "ccccc");         List
       
        
         > list = new ArrayList
         
          
           >(map.entrySet()); Collections.sort(list, new Comparator
           
            
             >() { public int compare(Map.Entry
             
               o1, Map.Entry
              
                o2) { return o1.getKey().compareTo(o2.getKey()); } }); String string = String.valueOf(list.get(0)) + String.valueOf(list.get(1)); System.out.println(string); }