I would like to parse the following json
{ "name":"Hello", "media_key":"I am Key", "media_blob_url":"I am Url", "media_blob_key": null}into the following object
class BlobType( @Json(name = "media_key") var mediaKey: String? = null, @Json(name = "media_blob_url") var mediaBlobUrl: String? = null, @Json(name = "media_blob_key") var mediaBlobKey: String? = null )class Item ( var name: String? = null, @Json(name="media_key") var blob: BlobType? = null)class AnotherItem ( var name: String? = null, var address: String? = null, @Json(name="media_key") var blob: BlobType? = null)and convert the object to flat json again.
NOTE: Something like Android Room Embedded where one object could be used to store multiple columns.
I probably need to write an Adapter for this purpose.
The main problem is adapter expect a single field to return a single result only (either a string or an object), but now I need to write a ToJson which convert a single object into 3 json fields and another FromJson to combine 3 json fields into a single object.
Somehow I manage to hack/hardcode ToJson which convert one object into 3 fields.
class BlobTypeJsonAdapter { /* @FromJson fun blogTypeFromJson(reader: JsonReader): BlobType { val item = BlobType() item.mediaKey = reader.nextString() System.out.println("nextName="+reader.nextName()) return item } */ @ToJson fun blogTypeToJson(writer: JsonWriter, item: BlobType) { writer.value(item.mediaKey) writer.name("media_blog_key").value(item.mediaBlobKey) writer.name("media_blog_url").value(item.mediaBlobUrl) }}val moshi = = Moshi.Builder() .add(BlobTypeJsonAdapter()) .add(KotlinJsonAdapterFactory()) .build()val adapter = moshi.adapter<Item>(Item::class.java)val item = Item(name="Hello", blob = BlobType(mediaKey = "I am Key", mediaBlobUrl = "I am Url"))val jsonString = adapter.toJson(item)Output
{ "name":"Hello", "media_key":"I am Key", "media_blob_url":"I am Url"}I didn't persuit this idea further because I feel the approach and solution is "unnatural" (merge multiple fields into object) and might introduce future confusion.
NOTE: Technically, I could make those fields private and create a object property with getter/setter to return a object based on these private fields.
NOTE: I could use EventJsonAdapter example, but would need to write an adapter for each class (Item and AnotherItem) and could not reuse the shared portion of BlobType only.
Besides, my moshi-fu is not strong enough and further experimentation will consume more time and introduce more complexity vs the benefit gained.
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