Question

I’m trying to parse a JSON feed using Gson in Android. I know the JSON is valid. I suspect that it is because the format is like this:

 "Info":[
 {

"Id":"",
"Name":"",
"Description":"",
"Date":""
 }

In order to parse this I need to “dot” in. Ex: Info.Name

How can I do this in a serialized DTO?

@SerializedName("Name")
public String name;

@SerializedName("Description")
public String desc;

@SerializedName("Date")
public String date;

I tried to put “Info.” in front of each serializedName but that didn’t work either. I also know my JSON parsing method works properly, because it’s used somewhere else with a different DTO. But in that parsing, I don’t have to “dotting” issue.

Can anyone help?

EDIT: I have tried everything you guys posted, and nothing works. The error says:

The JsonDeserializer failed to deserialize json object {"Info":[{".......

SECOND EDIT:
I was able to get rid of the error, but now it returns null. Haha, getting pretty damn frustrated right about now!

Answer 1

I am assuming that the actual JSON you are intaking is valid because the example you provided is not. In your JSON example, you have "Info":[ but there is no outer object containing the “Info” property, which is a must. The valid JSON would be:

{
 "Info": [
           {
             "Id":"",
             "Name":"",
             "Description":"",
             "Date":"",
           }
         ]
}

This is a JSON object that has a property “Info” which has a value that is a list of objects. This list of objects contains one object that has the properties “Id”, “Name”, “Description”, and “Date”, all of which have empty-string values.

Here is a quick tutorial on how to use GSON to parse a JSON feed such as the above JSON:

You will need a class to represent the items in the list:

public class InfoItem {
     public String Id;
     public String Name;
     public String Description;
     public String Date;
     public InfoItem() {}
}

And one to represent the list of Items:

public class InfoItemList extends LinkedList<InfoItem> {
    public InfoItemList() { super() };
}

This added complexity is because GSON cannot otherwise get the type of a generic collection from the class data.

And one to represent the overall JSON message:

public class InfoMessage {
    public InfoItemList Info;
    public InfoMessage() {};
}

And then just:

gson.fromJson(jsonString, InfoMessage.getClass());

If just de-serializing a collection:

Type listType = new TypeToken<List<InfoItem>>() {}.getType();
gson.fromJson(jsonString2, listType);