CODEWITHSUNDEEP
javaandroidjsongson
Jason Portnoy
Jason Portnoy

Reputation: 797

deserialize JSON data for different types of objects

Im using GSON on an Android device.

I have JSON data coming in, but it can come in the form of a few different objects.

This is how I think I need to handle it.

public class Command 
{
    public String Command;  
}


String json = {"Command":"Something", "date":"now"}

String command = gson.fromJson(message, Command.class);

Then switch on command

Switch(command)
{

case: something
//deserialize to "something" object;
break;

case: other somthing
//deserialize to "other somthing" object;
break;

case: object 3
//deserialize to "object 3" object;
break;

}

Does GSON have some sort of Auto Mapping to the best suited object, so i dont have to make a custom object handler and deseraialize the String twice?

Upvotes: 3

Views: 1833

Answers (2)

Joseph Helfert
Joseph Helfert

Reputation: 421

I would parse it as a general JsonObject using

    JsonParser parser = new JsonParser();
    JsonObject jsonObject = parser.parse(json).getAsJsonObject();

then find something unique about each json schema and then depending on which schema convert it to a bean using

    gson.fromJson(jsonObject, AppropriateBean.class);

Upvotes: 1

Janick Bernet
Janick Bernet

Reputation: 21184

I think an example of what you are trying to achieve is covered in the user guide. See the part about Serializing and Deserializing Collection with Objects of Arbitrary Types. They recommend to use the underlying parser API and then the fromGson method onward, so you don't have to parse intermediary objects, which sounds like a good approach to me. But the also provide two alternatives that you might try.

Upvotes: 0

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