Warum analysiert dieser Json mit Null-Attributen?

Question

Ich habe den folgenden Code, JSON und POJO, obwohl die JSON-Attribute Werte haben, das resultierende DataToUse-Objekt hat Null für Name und Datum. Gibt es eine besondere Möglichkeit, '@' im JSON zu behandeln? Ich habe ein anderes, genau ähnliches Stück Code, das richtig analysiert, aber es gibt kein '@'.

DataToUse dataToUse = new Gson().fromJson(json.toString(), DataToUse.class); 

JSON:

{“@name”: “A Name”,“@date”: "2017-12-11T18:00:00-05:00"} 

POJO:

public class DataToUse { 
    private String name; 
    private Date date; 

    public String getName() { return this.name; } 
    public void setName(String name) { this.name = name; } 

    public Date getDate() { return this.date; } 
    public void setDate(Date date) { this.date = date; } 
} 

Answer 1

unten Versuchen Sie, durch @SerializedName Anmerkung Hinzufügen

public class DataToUse { 
     @SerializedName("@name") 
     private String name; 
     @SerializedName("@date") 
     private Date date; 

     public String getName() { return this.name; } 
     public void setName(String name) { this.name = name; } 

     public Date getDate() { return this.date; } 
     public void setDate(Date date) { this.date = date; } 
    } 

Answer 2

Sie sollten die @ aus den Parametern entfernen

{“@name”: “A Name”,“@date”: "2017-12-11T18:00:00-05:00"} 


{“name”: “A Name”,“date”: "2017-12-11T18:00:00-05:00"} 

diese Lösung versuchen.

Answer 3

Normalerweise müssen Sie bei GSON eine Date-Parsing-Funktion im create gson-Prozess registrieren. Normalerweise mache ich eine Wrapper-Klasse namens JsonHelper, um mein Leben zu erleichtern. Beachten Sie das Datum Umgang Stück. Aber Sie haben wahrscheinlich Probleme mit Ihrem @ -Symbol, aber Sie müssen möglicherweise auch die Datumsformatierung verarbeiten.

/** 
* Created by App Studio 35 on 3/18/15. 
*/ 
public class JSONHelper { 

    /*////////////////////////////////////////////////////////// 
    // MEMBERS 
    */////////////////////////////////////////////////////////// 
    private static Gson mGson; //Google's JSON to Object Converter 
    private static final String TAG = JSONHelper.class.getSimpleName(); 


    /*////////////////////////////////////////////////////////// 
    // PROPERTIES 
    */////////////////////////////////////////////////////////// 
    protected static Gson getGson(){ 
     return mGson == null ? mGson = getGsonBuilder().create() : mGson; 
    } 


    /*////////////////////////////////////////////////////////// 
    // METHODS 
    */////////////////////////////////////////////////////////// 
    private static GsonBuilder getGsonBuilder(){ 
     //Used for Building a Gson Converter a Google Product for JSON Translation to Objects 
     GsonBuilder builder = new GsonBuilder(); 
     //Created as Static so Fragments can easily use the same Builder. 
     builder.registerTypeAdapter(Date.class, new JsonDeserializer<Date>() { 

      @Override 
      public Date deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException { 

       //Specify the way we format Dates in this Converter 
       SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss a", Locale.getDefault()); 
       format.setTimeZone(TimeZone.getTimeZone("UTC")); 
       String date = json.getAsJsonPrimitive().getAsString(); 

       try { 
        return format.parse(date); 

       } catch (ParseException e) { 
        Log.e(TAG, "getGsonBuilder failed to register Date: " + e.getMessage()); 
        throw new RuntimeException(e); 

       } 
      } 
     }); 
     return builder; 
    } 
    /** 
    * 
    * @param objectToConvert to convert to Json 
    * @param classType the class that we are serializing from into a String 
    * @return 
    */ 
    public static String toJson(Object objectToConvert, Class classType){ 
     try { 
      String msg = ""; 
      //Get String from Gson converter for Class Type 
      msg = getGson().toJson(objectToConvert, classType); 

      //Return String of Json from passed in Object 
      return msg; 

     } catch (Exception e) { 
      Log.e(TAG, e.getMessage() == null ? "null" : e.getMessage()); 
      return ""; 

     } 
    } 
    /** 
    * 
    * @param objectToConvert to convert to Json 
    * @param classType the Type that we are serializing from into a String 
    * @return 
    */ 
    public static String toJson(Object objectToConvert, Type classType){ 
     try { 
      String msg = ""; 
      //Get String from Gson converter for Class Type 
      msg = getGson().toJson(objectToConvert, classType); 

      //Return String of Json from passed in Object 
      return msg; 

     } catch (Exception e) { 
      Log.e(TAG, e.getMessage() == null ? "null" : e.getMessage()); 
      return ""; 

     } 
    } 
    /** 
    * 
    * @param objectToConvert Object to convert to JSON string 
    * @return json string to represent the passed object 
    */ 
    public static String toJson(Object objectToConvert){ 
     try { 
      String msg = ""; 
      //Get String from Gson converter for Class Type 
      msg = getGson().toJson(objectToConvert); 

      //Return String of Json from passed in Object 
      return msg; 

     } catch (Exception e) { 
      Log.e(TAG, e.getMessage() == null ? "null" : e.getMessage()); 
      return ""; 

     } 
    } 
    /** 
    * 
    * @param json String to convert into Object for the class that was passed 
    * @param classType the class that we are serializing from 
    * @return 
    */ 
    public static Object fromJson(String json, Class classType){ 
     try { 
      //Get Object from Gson converter of Json 
      Object obj = getGson().fromJson(json, classType); 

      //Return filled in object of passed in Class Type 
      return obj; 

     } catch (Exception e) { 
      Log.e(TAG, e.getMessage() == null ? "null" : e.getMessage()); 
      return null; 

     } 
    } 
    /** 
    * 
    * @param json String to convert into Json for the class that was passed 
    * @param classType the Type that we are serializing from 
    * @return 
    */ 
    public static Object fromJson(String json, Type classType){ 
     try { 
      //Get Object from Gson converter of Json 
      Object obj = getGson().fromJson(json, classType); 

      //Return filled in object of passed in Class Type 
      return obj; 

     } catch (Exception e) { 
      Log.e(TAG, e.getMessage() == null ? "null" : e.getMessage()); 
      return null; 

     } 
    } 
    /** 
    * 
    * @param jsonElement JsonElement to convert into Object for the class that was passed 
    * @param classType the class that we are serializing from 
    * @return 
    */ 
    public static Object fromJson(JsonElement jsonElement, Class classType){ 
     try { 
      //Get Object from Gson converter of Json 
      Object obj = getGson().fromJson(jsonElement, classType); 

      //Return filled in object of passed in Class Type 
      return obj; 

     } catch (Exception e) { 
      Log.e(TAG, e.getMessage() == null ? "null" : e.getMessage()); 
      return null; 

     } 
    } 
    /** 
    * 
    * @param jsonElement String to convert into Object for the class that was passed 
    * @param classType the class that we are serializing from 
    * @return 
    */ 
    public static Object fromJson(JsonElement jsonElement, Type classType){ 
     try { 
      //Get Object from Gson converter of Json 
      Object obj = getGson().fromJson(jsonElement, classType); 

      //Return filled in object of passed in Class Type 
      return obj; 

     } catch (Exception e) { 
      Log.e(TAG, e.getMessage() == null ? "null" : e.getMessage()); 
      return null; 

     } 
    } 
    public static Map<String, Object> jsonToMap(JSONObject json) throws JSONException { 
     Map<String, Object> retMap = new HashMap<String, Object>(); 

     if(json != JSONObject.NULL) { 
      retMap = toMap(json); 
     } 
     return retMap; 
    } 
    public static Map<String, Object> toMap(JSONObject object) throws JSONException { 
     Map<String, Object> map = new HashMap<String, Object>(); 

     Iterator<String> keysItr = object.keys(); 
     while(keysItr.hasNext()) { 
      String key = keysItr.next(); 
      Object value = object.get(key); 

      if(value instanceof JSONArray) { 
       value = toList((JSONArray) value); 
      } 

      else if(value instanceof JSONObject) { 
       value = toMap((JSONObject) value); 
      } 
      map.put(key, value); 
     } 
     return map; 
    } 
    public static List<Object> toList(JSONArray array) throws JSONException { 
     List<Object> list = new ArrayList<Object>(); 
     for(int i = 0; i < array.length(); i++) { 
      Object value = array.get(i); 
      if(value instanceof JSONArray) { 
       value = toList((JSONArray) value); 
      } 

      else if(value instanceof JSONObject) { 
       value = toMap((JSONObject) value); 
      } 
      list.add(value); 
     } 
     return list; 
    } 

}