Integer value will always deserialize to be java.lang.Double

[Luis Ashurei]

The client code looks like:
public class MyTest {
class Example {
Object p;
}
public static void main(final String args[]) {
Gson gson = new Gson();
Example a = gson.fromJson("{\"p\":1}", Example.class);
System.out.println(a.p.getClass().getName()); //
java.lang.Double
}
}

The gson source code looks like:
com.google.gson.internal.bind.ObjectTypeAdapter.read(JsonReader in)

case NUMBER:
return in.nextDouble();

It's not so good, is it?
Should JsonToken add enum like INTEGER, FLOAT etc. ?

[Jesse Wilson]

If an Integer is what you want, declare the type of Example's 'p' field to be Integer or int.

[Luis Ashurei]

I know i can explicit declare the type to Integer to get
java.lang.Integer.
But dynamic declare is useful in some cases, such as reflection,
dynamic object etc.

[Inderjeet Singh]

For performance reason, Gson no longer tries to figure out the minimum type that can retain the precision. (Earlier versions of Gson used to do so). It just uses double. I would argue that you should rethink the design of your model class Example, or register a type-adapter for it.

HTH

Inder

[h.schenk]

Can you say me, which is the latest version which tries to figure out
the correct type?

[Jesse Wilson]

Gson 1.7.