无法使用GSON API

Question

收到以下异常反序列化对象进行反序列化对象与列表：

com.google.gson.JsonParseException: 
    The JsonDeserializer [email protected]a 
    failed to deserialized json object 
     {"com.gsicommerce.analytics.platform.model.webstore.AnalyticsProduct": 
      [ 
       {"id":"3680231","longTitle":"Graco SnugRide Infant Car Seat - Pippin","available":"true"} 
      ] 
     } 
    given the type [email protected] 

这里是我试图反序列化类：

public class TrusRegWishAddItemEvent implements Serializable { 
    static final long serialVersionUID = 1L; 
    private final List<AnalyticsProduct> items; 

    private TrusRegWishAddItemEvent() { 
     items = null; 
    } 

    public TrusRegWishAddItemEvent(List<AnalyticsProduct> items) { 
     this.items = items; 
    } 

    public List<AnalyticsProduct> getItems() { 
     return items; 
    }  
} 

public class AnalyticsProduct implements Serializable { 
    static final long serialVersionUID = 1L; 
    private final long id; 
    private final String longTitle; 
    private final boolean available; 

    public AnalyticsProduct() { 
     id = 0; 
     longTitle = null; 
     available = false; 
    } 

    public AnalyticsProduct(long id, String longTitle, boolean available) { 
     this.id = id; 
     this.longTitle = longTitle; 
     this.available = available; 
    } 

    public long getId() { 
     return id; 
    } 

    public String getLongTitle() { 
     return longTitle; 
    } 

    public boolean isAvailable() { 
     return available; 
    } 
} 

请指南。

Answer 1

如果JSON是

{ 
    "items": 
    [ 
    { 
     "id":"3680231", 
     "longTitle":"Graco SnugRide Infant Car Seat - Pippin", 
     "available":"true" 
    } 
    ] 
} 

然后将下面的示例使用GSON容易地反序列化/序列化到/从原来的问题相同的Java数据结构。

public static void main(String[] args) throws Exception 
    { 
    Gson gson = new Gson(); 
    TrusRegWishAddItemEvent thing = gson.fromJson(new FileReader("input.json"), TrusRegWishAddItemEvent.class); 
    System.out.println(gson.toJson(thing)); 
    } 

相反，如果JSON必须

{"com.gsicommerce.analytics.platform.model.webstore.AnalyticsProduct": 
     [ 
      {"id":"3680231","longTitle":"Graco SnugRide Infant Car Seat - Pippin","available":"true"} 
     ] 
    } 

然后有必要的JSON元素名称"com.gsicommerce.analytics.platform.model.webstore.AnalyticsProduct"转换为Java成员items。为此，Gson提供了一些机制，其中最简单的方法就是如下注释TrusRegWishAddItemEvent中的items属性。

class TrusRegWishAddItemEvent implements Serializable 
{ 
    static final long serialVersionUID = 1L; 

    @SerializedName("com.gsicommerce.analytics.platform.model.webstore.AnalyticsProduct") 
    private final List<AnalyticsProduct> items; 

    ... 
} 

但是，如果没有这@SerializedName注释试图反序列化时GSON不抛出一个异常，而是它只是构建与items为空引用一个TrusRegWishAddItemEvent实例。所以，目前还不清楚在原始问题中如何生成错误消息。