bleak vector
Hey having a problem with Json & Gson and hoping someone might have a little more knowledge:
I'm trying to convert a string (json) to an object using GSON.fromJson(json, Grant.class)
My string of json is: {"id":"a31ed","rank":"merchant","scope":"earth","createdAt":1694437862922,"duration":1814400000}
And the stack is:
java.lang.IllegalStateException: Expected BEGIN_OBJECT but was STRING
I've been looking at stackoverflow for answers for over 2 hours but nothing has helped
stiff ore
Try making a GsonDeserializer for your needs. This object is simple but maybe for scalability and maybe it'll even help get rid of the error
Creating one is super easy
If I find one I've made, I can send you an example
bleak vector
Whoops, it's Grant.class not Group
I'm using an adapter to only serialize/deserialze certain values of the Grant:
public class GrantAdapter implements JsonSerializer<Grant>, JsonDeserializer<Grant> {
@Override
public JsonElement serialize(Grant grant, Type type, JsonSerializationContext jsonSerializationContext) {
JsonObject jsonObject = new JsonObject();
jsonObject.addProperty("id", grant.getDocumentID());
jsonObject.addProperty("rank", grant.getRank().getId());
jsonObject.addProperty("scope", grant.getScope().getId());
jsonObject.addProperty("createdAt", grant.getCreatedAt());
jsonObject.addProperty("duration", grant.getDuration());
return jsonObject;
}
@Override
public Grant deserialize(JsonElement jsonElement, Type type, JsonDeserializationContext jsonDeserializationContext) throws JsonParseException {
JsonObject object = jsonElement.getAsJsonObject();
String id = object.get("id").getAsString();
String rank = object.get("rank").getAsString();
String scope = object.get("scope").getAsString();
long createdAt = object.get("createdAt").getAsLong();
long duration = object.get("duration").getAsLong();
CorePlugin plugin = CorePlugin.getInstance();
Rank finalRank = plugin.getRankManager().getRankById(rank);
Scope finalScope = plugin.getScopeManager().getScopeById(scope);
if (finalRank == null || finalScope == null) {
return null;
}
return new Grant(id, finalRank, finalScope, createdAt, duration);
}
}
Oh you already have a deserializer
stiff ore
Well your deserializer looks fine
Did you add it to your Gson?
E.g. my Gson initializition in one of the projects is
private void initJSON() {
gson = GsonBuilder()
.setPrettyPrinting()
.registerTypeAdapter(Values.class, new ConfigurationDeserializer())
.registerTypeAdapter(Messages.class, new MessagesDeserializer())
.registerTypeAdapter(MinesManager.class, new MinesDeserializer(this))
.registerTypeAdapter(MinesManager.class, new MinesSerializer())
.setLenient()
.create();
}
grim copper
lol kotlin
bleak vector
So just to make sure:
Gson GSON = new GsonBuilder()
.registerTypeAdapter(Grant.class, GrantAdapter.class)
.create();
Should be good yeah, though don't name it GSON but name it gson
Otherwise it looks like you're calling a class
Wait no
Not GrantAdapter.class I don't think
It should be an instance of it
new GrantAdapter()
Actually both seem to be possible
Try both
bleak vector
@stiff ore Thank you so much! I've been banging my head against a wall the past 2 hours 😆
I was using @JsonAdapter(GrantAdapter.class) on the Grant.class which worked on another project for me, anyway glad that's fixed 🙂