Suppose to have an abstract class, say A, and two non-abstract subclasses, say A1 and A2. I want to "deserialize" them from a json format by using the GSON library.

E.g. I get an array of A objects.

int n = ...;
A[] list = new A[n];
A[0] = new A1(....);
A[1] = new A2(....);
...

which someone converted to a JSON string as follows:

String json = (new Gson()).toJson(list);

Finally, if I try to deserialize as follows

A[] deserializedList =  (new Gson()).fromJson(json, A[].class);

then I has got an error, since the GSON default deserializer finds an abstract class (i.e. A) and it is not capable of guessing the subclass type.

How can I solve this?

PS: I read about custom deserializer, but I don't understand how to use them in this case.

java gson
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