对象转换 json 字符串和 json转换对象的几种方式

1、使用阿里巴巴的fastjson方式处理。

public static void main(String[] args) throws JSONException { User user = new User(); user.setUserNo("1"); user.setName("小明"); // 对象转成json字符串
        String jsonStr = JSON.toJSONString(user); System.out.println(jsonStr); //json字符串转成对象
        User user1 = JSON.parseObject(jsonStr,User.class); System.out.println(user1.getName()); }

2、使用org.json包对象转换json字符串

public static void main(String[] args) throws JSONException { User user = new User(); user.setUserNo("1"); user.setName("小明"); String json = new JSONObject(user).toString(); System.out.println(json); // json字符串转成对象
        JSONObject jsonObject = new JSONObject(json); String name = jsonObject.getString("name"); String userNo = jsonObject.getString("userNo"); User user1 = new User(); user1.setName(name); user1.setUserNo(userNo); System.out.println(user1.getName()); }

3、使用gson方式处理json字符串

public static void main(String[] args) { User user = new User(); user.setUserNo("1"); user.setName("小明"); Gson gson = new Gson(); // 对象转换json字符串
        String json = gson.toJson(user); System.out.println(json); //json字符串转成对象
        User user1 = gson.fromJson(json,User.class); System.out.println(user1.getName()); }

4、Jackson

public static void main(String[] args) { User user = new User(); user.setUserNo("1"); user.setName("小明"); ObjectMapper mapper = new ObjectMapper(); try { // 对象转成json字符串
            String json = mapper.writeValueAsString(user); System.out.println(json); //json字符串转成对象
            User user1 = mapper.readValue(json,User.class); System.out.println(user1.getName()); } catch (JsonProcessingException e) { // TODO Auto-generated catch block
 e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block
 e.printStackTrace(); } }

5、Json-Lib

public static void main(String[] args) throws JSONException { User user = new User(); user.setUserNo("1"); user.setName("小明"); // 转成json字符串
        JSONObject jsonObject = JSONObject.fromObject(user); String json = jsonObject.toString(); System.out.println(json); // json字符串转成对象
        JSONObject jsonObject1 = JSONObject.fromObject(json); User user1 = (User) JSONObject.toBean(jsonObject1, User.class); System.out.println(user1.getName()); }