I'm trying to deserialize the following structure
{ meta: { keywords: [a, b, c, d]} ... }
other valid structures are
{ meta: { keywords: "a,b,c,d"} ... }
and
{ meta: {keywords: "a"} ...}
I have this classes
public class Data {
@PropertyName("meta")
MetaData meta;
...
}
public class MetaData {
List<String> keywords;
...
}
and a custom deserializer
public static class CustomDeserilizer implements JsonDeserializer<MetaData>{
@Override
public MetaData deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {
List<String> keywords = null;
Gson gson = new Gson();
MetaData metaData = gson.fromJson(json, AppMetaData.class);
JsonObject jsonObject = json.getAsJsonObject();
if (jsonObject.has("keywords")) {
JsonElement elem = jsonObject.get("keywords");
if (elem != null && !elem.isJsonNull()) {
if (jsonObject.get("keywords").isJsonArray()) {
keywords = gson.fromJson(jsonObject.get("keywords"), new TypeToken<List<String>>() {
}.getType());
} else {
String keywordString = gson.fromJson(jsonObject.get("keywords"), String.class);
keywords = new ArrayList<String>();
list.addAll(Arrays.asList(keywordString.split(",")));
}
}
}
metaData.setKeywords(keywords);
}
Then I try to apply the deserilizer:
Gson gson = new GsonBuilder()
.registerTypeAdapter(Data.class,new CustomDeserilizer())
.create();
But I get a parsing error , because is trying to deserialize Data instead of MetaData, how can I apply this deserializer to make it work right?
I solved it creating a deserializer for my class Data.
public static class DataDeserilizer implements JsonDeserializer {
@Override
public Data deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {
Gson gson = new Gson();
Data data = gson.fromJson(json, Data.class);
JsonObject jsonObject = json.getAsJsonObject();
if (jsonObject.has("meta")) {
JsonElement elem = jsonObject.get("meta");
if (elem != null && !elem.isJsonNull()) {
Gson gsonDeserializer = new GsonBuilder()
.registerTypeAdapter(MetaData.class, new CustomDeserilizer())
.create();
gsonDeserializer.fromJson(jsonObject.get("meta"), Data.class);
}
}
return data;
}
}
And
Gson gson = new GsonBuilder()
.registerTypeAdapter(Data.class,new DataDeserilizer())
.create();
Pretty obvious, but is there a more elegant solution?