Failure to deserialize an EnumSet

[Maurice Balick]

I can't figure out how to serialize/deserialize an EnumSet. I thought that using TypeToken during deserialization would do the trick, but apparently not.

Here is a trivial example of what I am doing that fails:

import com.google.gson.Gson;

import com.google.gson.reflect.TypeToken;

import java.util.EnumSet;

public class Test2 {

    enum Color { red, blue, green, yellow, thistle }

    public static void main(String[] args) throws Exception {

        Gson gson = new Gson();

        EnumSet<Color> foo = EnumSet.of(Color.blue, Color.red);

        String json = gson.toJson(foo);

        EnumSet<Color> bar = (EnumSet<Color>)gson.fromJson(json, new TypeToken<EnumSet<Color>>() {}.getType());

        System.out.printf("foo: " + foo + "\nbar: " + bar + '\n');

    }

}

When I run this code, it fails with this error:

Exception in thread "main" java.lang.ClassCastException: java.util.LinkedHashSet cannot be cast to java.util.EnumSet

at com.nf.tests.exp.Test2.main(Test2.java:line in red)

I do not understand why gson.fromJson(...) returns a java.util.LinkedHashSet when it is asked for an EnumSet.

As always, any hint of what I am doing wrong would be much appreciated.

--Maurice

[Inderjeet Singh]

Seems like a bug in Gson. I added it at: http://code.google.com/p/google-gson/issues/detail?id=509

We will try to fix it in the next release.

Inder

coauthor, Gson

[Inderjeet Singh]

This bug has now been fixed in https://code.google.com/p/google-gson/source/detail?r=1228 and should make it to Gson 2.2.3

[naseem regragui]

It just so happens I have run into this problem today. Do you have a target release date for 2.2.3?

Thanks,

Naseem

[Inderjeet Singh]

Plan is to release it today!