試圖解析與GSON的JSON

Question

我想解析我的Android應用程序上的GSON庫的JSON。我能正確解析JSON陣列，但現在我需要解析另一個JSON，這個estructure：

{ 
    "articles": [ 
     { 
      "article": { 
       "articleId": 1, 
       "articleName": "Bocadillo de calamares", 
       "merchantId": 2, 
       "price": 3.5 
      }, 
      "computable": true, 
      "orderArticleId": 3157, 
      "orderId": 203, 
      "price": 3.5, 
      "requestedDate": "2012-11-19 13:15:20", 
      "shared": true, 
      "status": "AS01_INITIAL" 
     }, 
     { 
      "article": { 
       "articleId": 3, 
       "articleName": "Desayuno", 
       "merchantId": 2, 
       "price": 2.2 
      }, 
      "computable": true, 
      "orderArticleId": 3158, 
      "orderId": 203, 
      "price": 0, 
      "requestedDate": "2012-11-19 13:17:30", 
      "shared": true, 
      "status": "AS01_INITIAL" 
     }, 
     { 
      "article": { 
       "articleId": 2, 
       "articleName": "Café", 
       "merchantId": 2, 
       "price": 1.1 
      }, 
      "computable": true, 
      "orderArticleId": 3156, 
      "orderId": 203, 
      "price": 1.1, 
      "requestedDate": "2012-11-19 13:15:20", 
      "shared": true, 
      "status": "AS01_INITIAL" 
     }, 
     { 
      "article": { 
       "articleId": 1, 
       "articleName": "Bocadillo de calamares", 
       "merchantId": 2, 
       "price": 3.5 
      }, 
      "computable": true, 
      "orderArticleId": 3155, 
      "orderId": 203, 
      "price": 3.5, 
      "requestedDate": "2012-11-19 12:40:17", 
      "shared": true, 
      "status": "AS01_INITIAL" 
     } 
    ], 
    "comment": null, 
    "creationDate": "2012-11-19 12:06:41", 
    "customer": { 
     "creationDate": 1353321506000, 
     "customerId": 152, 
     "devices": [ 
      { 
       "customerId": 152, 
       "deviceId": "2000", 
       "phone": null 
      } 
     ], 
     "image": false, 
     "mail": null, 
     "name": null, 
     "password": null 
    }, 
    "finishDate": null, 
    "group": 0, 
    "groupOrders": [], 
    "location": { 
     "location": "Table 1", 
     "locationId": 1, 
     "shopId": 2 
    }, 
    "orderId": 203, 
    "parentOrderId": 192, 
    "score": null, 
    "shopId": 2, 
    "status": "OS01_INITIAL", 
    "ticketUrl": null, 
    "tip": null, 
    "total": 0, 
    "totalArticles": 0, 
    "type": "BILL" 
} 


I have a Order.class like this: 

    public class Order { 

    private final String orderId; 
    (....) 
    private final ArrayList<Articles> articles; 
    private final String group; 


    public Order() { 

     orderId = ""; 
     (....) 

     articles = new ArrayList<Articles>(); 
     group = ""; 
    } 

    public String getOrderId() { 
     return orderId; 
    } 

    (... All getters for each element) 

    public ArrayList<Articles> getArticles() { 
     return articles; 
    } 
} 

而一個Articles.class

public class Articles { 

private final String orderArticleId; 
(...) 
private final ArrayList<Article> article; 

public Articles() { 
    orderArticleId = ""; 
    (....) 
    article = new ArrayList<Article>(); 

}; 

public String getPrice() { 
    return price; 
} 

(....All getters for each element) 

public ArrayList<Article> getArticle() { 
    return article; 
} 

}

而且，在我的主活動我試圖得到所有的信息whith：

final Gson gson = new Gson(); 
    Order o = gson.fromJson(jsonData, Order.class); 
    System.out.println(" - " + o.getOrderId()); 

工作正常，但如果我想獲得Articles info，va lues是空的，我不知道我怎麼能得到它。

我嘗試用類似的東西：

Type collectionType = new TypeToken<List<Merchants>>() { 
      }.getType(); 
      data = gson.fromJson(response, collectionType); 

我嘗試使用ArticlesWrapper，但我不知道如何做到這一點沒錯。但我想我忘記了一些東西......而我不知道是什麼。 在應用程序的另一部分，我正確反序列化JSON，因爲它是一個數組，但在這種情況下，我不知道如何正確地獲取所有數據。

如果您需要更多信息，我會爲您提供！ 謝謝！

Answer 1

這是因爲您沒有正確地將JSON結構轉換爲Java POJO，基本上忽略了一些字段具有以下結構。

+ Order 
    + List<BigArticle> articles 
    + Customer customer 
    + Location location 
    + other basic fields 

+ BigArticle 
    + Article article 
    + other basic fields 

+ Article 
    + basic fields 

+ Customer 
    + List<Device> devices 
    + other basic fields 

+ Device 
    + basic fields 

+ Location 
    + basic fields 

所以，你應該結束了6個Java的POJO的是GSON應該能夠反序列化JSON數據來填充。

我剛剛在此處將您的JSON結構轉換爲POJO，並且我已將Dates作爲字符串來簡化解析。如果您想要正確填充java.util.Date，則必須自定義GSon實例。

主類

public class Main { 
    public static void main(String[] args) { 
     String jsonData = "..."; 
     final Gson gson = new Gson(); 
     Order o = gson.fromJson(jsonData, Order.class); 
     System.out.println("orderId: " + o.getOrderId()); 
     System.out.println("first article price: " + o.getArticles().get(0).getPrice()); 
     System.out.println("second article status: " + o.getArticles().get(1).getStatus()); 
     System.out.println("third article requested date: " + o.getArticles().get(2).getRequestedDate()); 
    } 
} 

訂購

public class Order { 
    private List<BigArticle> articles; 
    private String comment; 
    private String creationDate; 
    private Customer customer; 
    private String finishDate; 
    private int group; 
    private List<Integer> groupOrders; 
    private Location location; 
    private int orderId; 
    private int parentOrderId; 
    private int score; 
    private int shopId; 
    private String status; 
    private String ticketUrl; 
    private String tip; 
    private int total; 
    private int totalArticles; 
    private String type; 

    // getters and setters 
} 

BigArticle

public class BigArticle { 
    private Article article; 
    private boolean computable; 
    private int orderArticleId; 
    private int orderId; 
    private double price; 
    private String requestedDate; 
    private boolean shared; 
    private String status; 

    // getters and setters 
} 

條

public class Article { 
    private int articleId; 
    private String articleName; 
    private int merchantId; 
    private double price; 

    // getters and setters 
} 

客戶

public class Customer { 
    private long creationDate; 
    private int customerId; 
    private List<Device> devices; 
    private boolean image; 
    private String mail; 
    private String name; 
    private String password; 

    // getters and setters 
} 

設備

public class Device { 
    private int customerId; 
    private String deviceId; 
    private String phone; 

    // getters and setters 
} 

位置

public class Location { 
    private String location; 
    private int locationId; 
    private int shopId; 

    // getters and setters 
} 

輸出

orderId: 203 
first article price: 3.5 
second article status: AS01_INITIAL 
third article requested date: 2012-11-19 13:15:20