JSON parse single string to object

Question

is there any easy way to to convert this json:

{
    ...,
    "pictures": [
        "url1",
        "url2"
    ],
    ...
}

to

List<Picture> pictures

where Picture is:

class Picture{
      String url;
}

It won't work as above, because I have an exception, saying

Expected BEGIN_OBJECT but was STRING

Answer 1

You need to implement a custom deserializer for this. Should be looking like this (I didn't try to execute, but that should give you the idea where to start, presumably you have a public constructor with String argument in your Picture.class )

private class PictureDeserializer implements JsonDeserializer<Picture> {
  public Picture deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
      throws JsonParseException {
    return new Picture(json.getAsJsonPrimitive().getAsString());
  }
}

It should be registered:

GsonBuilder gson = new GsonBuilder();
gson.registerTypeAdapter(Picture.class, new PictureDeserializer());