public static void printMap(Map map,String prefix){
        for(Map.Entry entry : (Set<Map.Entry>)map.entrySet()){
            if(entry.getValue() instanceof  Map){
                System.out.println(prefix+"map:"+entry.getKey());
                printMap((Map)entry.getValue(),prefix+"--");
            }else{
                System.out.println(prefix+entry.getKey()+":"+entry.getValue());
            }
        }
    }