Deserialization with Gson.fromJson() should *ignore* missing fields

[GoogleCodeExporter]

What steps will reproduce the problem?

1. Create a simple *non-static* class which initializes default values for some 
fields:

    public class Test {

        int x = -1;
        String s = "Hello";
    }

2. Create new Gson and call `fromJson()` with missing fields:

    Test t = new Gson().fromJson("{}", Test.class);
    System.out.println(String.format("x=[%s] s=[%s]", t.x, t.s));

>> Results: x=[0] s=[null]

    Test t = new Gson().fromJson("{\"x\": 1}", Test.class);
    System.out.println(String.format("x=[%s] s=[%s]", t.x, t.s));

>> Results: x=[1] s=[null]

What is the expected output? What do you see instead?

As the test cases, I would like to expect default value for each field to be 
the one that the class initializes. For instance with the first test case, `x` 
should be `-1` and `s` should be "Hello".

What version of the product are you using? On what operating system?

 - Gson 2.2.3
 - OSes:
   + Fedora 18, 64 bit with OpenJDK 1.7.0_19;
   + Android API 4 and API 17;

Thanks,
Hai

Original issue reported on code.google.com by haibison...@gmail.com on 5 May 2013 at 8:23

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Is this still an issue.  Did u try it in 2.2.4?

Its working for me on Windows with GSON 2.2.4

Original comment by haripr...@gmail.com on 3 Aug 2013 at 1:22

[GoogleCodeExporter]

Hari,

Yes it is. I've just tested with Gson 2.2.4 on Fedora 19, 64 bit with OpenJDK 
64-Bit Server VM (build 23.7-b01, mixed mode).

Original comment by haibison...@gmail.com on 4 Aug 2013 at 11:35

[GoogleCodeExporter]

Apparently, if you have a default constructor for the class, it will work as 
you like.

public Test() { }

and that should be enough for the instance variables to be initialized as 
declared.

Original comment by krt...@gmail.com on 22 Nov 2013 at 1:12

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@krt...

Thanks for your help. Unfortunately it's not working. I still got "x=[0] 
s=[null]". Gson v2.2.4.

Original comment by haibison...@gmail.com on 22 Nov 2013 at 7:28

[GoogleCodeExporter]

Confirm, this is still not working.
No way to assign default values for fields.
If field is missing in JSON it is deserialized as null.
Gson v2.2.4

Original comment by kamui.ji...@gmail.com on 31 Jan 2014 at 7:16

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This is most probably related to issue 495, see the links in the posting from 
Jun 23, 2013.

Original comment by Maaarti...@gmail.com on 2 Feb 2014 at 12:32

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[deleted comment]

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This issue doesn't exist with version 2.3.1.

Original comment by xz4...@gmail.com on 16 Jun 2015 at 7:55