HashMap转JSON字符串，JSON字符串转HashMap

       HashMap<Long,String> hashMap = new HashMap<>();
        hashMap.put(1000000000001L,"一");
        hashMap.put(1000000000002L,"二");
        hashMap.put(1000000000003L,"三");

        JSONObject jsonObject = new JSONObject();
        jsonObject.put("jsonTest",JSONObject.toJSONString(hashMap));  //HashMap转json字符串
        System.out.println("HashMap转json字符串的结果为：");
        System.out.println(jsonObject.getString("jsonTest"));

        String jsonString = jsonObject.getString("jsonTest");
        HashMap<Long,String> hashMap1 = JSON.parseObject(jsonString, HashMap.class); //json字符串转HashMap
        System.out.println("json字符串转HashMap，遍历HashMap取key:valued的值为：");
        for (Long key : hashMap1.keySet()) {
            String value = hashMap1.get(key);
            System.out.println(key + ":" + value);
        }

运行结果