@Test
    public void mapTest() throws Exception {
        Map map  = new HashMap();
                map.put("1", UUID.randomUUID().toString()) ;
                map.put("4", UUID.randomUUID().toString()) ;
                Map<Integer ,String> integerStringMap = new HashMap<>() ;
                integerStringMap.put(1,UUID.randomUUID().toString()) ;
        //        integerStringMap = map;
                if (!integerStringMap.isEmpty()){
                    for ( Iterator<Map.Entry<Integer, String>> iterator = integerStringMap.entrySet().iterator();iterator.hasNext();){
                        Map.Entry<Integer, String> next = iterator.next();
                        System.out.println(next.getKey()+"-"+next.getValue());
                        System.out.println(next.getKey() instanceof Integer);
                        System.out.println(next.getValue() instanceof String);
                    }
                }
                //print result
                /**
                 * 1-aeec41b6-bb7c-4e77-a57c-70a416bc03eb
                 * false
                 * true
                 * 4-e02bb587-9714-4873-9b6c-5e2d4494117f
                 * false
                 * true
                 */
    }