SerializedName should allow the @ character

[GoogleCodeExporter]

I'm having trouble deserialising json of the following form:

{ "@value" : 3 }

As far as I can tell this is valid json, however gson's JsonFieldNameValidator 
appears to dislike the presence of the @ character.

I'm declaring the gson java class:

static class MyObj {
    @SerializedName("@value")
    int value;
}

I'd expect this to work, but instead I get an exception:

What is the expected output? What do you see instead?
xception in thread "main" java.lang.IllegalArgumentException: @value is not a 
valid JSON field name.
    at com.google.gson.JsonFieldNameValidator.validate(JsonFieldNameValidator.java:52)
    at com.google.gson.SerializedNameAnnotationInterceptingNamingPolicy.translateName(SerializedNameAnnotationInterceptingNamingPolicy.java:45)
    at com.google.gson.JsonObjectDeserializationVisitor.getFieldName(JsonObjectDeserializationVisitor.java:92)
    at com.google.gson.JsonObjectDeserializationVisitor.visitFieldUsingCustomHandler(JsonObjectDeserializationVisitor.java:97)
    at com.google.gson.ObjectNavigator.navigateClassFields(ObjectNavigator.java:158)
    at com.google.gson.ObjectNavigator.accept(ObjectNavigator.java:131)
    at com.google.gson.JsonDeserializationVisitor.visitChild(JsonDeserializationVisitor.java:107)
    at com.google.gson.JsonDeserializationVisitor.visitChildAsObject(JsonDeserializationVisitor.java:95)
    at com.google.gson.JsonObjectDeserializationVisitor.visitObjectField(JsonObjectDeserializationVisitor.java:61)
    at com.google.gson.ObjectNavigator.navigateClassFields(ObjectNavigator.java:164)
    at com.google.gson.ObjectNavigator.accept(ObjectNavigator.java:131)
    at com.google.gson.JsonDeserializationContextDefault.fromJsonObject(JsonDeserializationContextDefault.java:73)
    at com.google.gson.JsonDeserializationContextDefault.deserialize(JsonDeserializationContextDefault.java:51)
    at com.google.gson.Gson.fromJson(Gson.java:568)
    at com.google.gson.Gson.fromJson(Gson.java:515)
    at com.google.gson.Gson.fromJson(Gson.java:484)
    at com.google.gson.Gson.fromJson(Gson.java:434)
    at com.google.gson.Gson.fromJson(Gson.java:406)

I'm using gson 1.6 on Ubuntu.

Original issue reported on code.google.com by t.denley on 17 Feb 2011 at 9:11

[GoogleCodeExporter]

Similar to issue 121, where the hyphen character was added.
http://code.google.com/p/google-gson/issues/detail?id=121

Original comment by t.denley on 17 Feb 2011 at 9:13

[GoogleCodeExporter]

I have the same problem, so i have done a patch to pass this.

Warning, the issue 121 isn't about the @ caracter.

Original comment by ybonnel on 5 Apr 2011 at 6:40

Attachments:

• patchIssue290.diff

[GoogleCodeExporter]

Thanks for doing a patch. I think that allowing a bypass of field validation is 
a bit overkill though. I'd suggest the following patch might be a bit more 
targeted.

Original comment by t.denley on 5 Apr 2011 at 10:20

Attachments:

• gson_issue290.diff

[GoogleCodeExporter]

Are there any committers reviewing bugs at the moment?
Given the simplicity of this fix, is there any chance of getting it into 1.7?

Original comment by t.denley on 7 Apr 2011 at 6:21

[GoogleCodeExporter]

Unfortunately, with certain browsers this would cause problems while doing 
evals on JSON objects. That said, I'm not too worried about relaxing this 
constraint on Gson since we should be aligning more closely with the JSON spec 
rather than focusing on what certain clients can and cannot handle.

Original comment by joel.leitch@gmail.com on 12 Apr 2011 at 4:42

• Changed state: Accepted

[GoogleCodeExporter]

I'm surprised that we do any name policy enforcement at all. JSON permits 
anything in a name; we should too. If that means we can't map a property to a 
field, then we have to fail at runtime.

Original comment by limpbizkit on 12 Apr 2011 at 4:48

[GoogleCodeExporter]

Fixed in r798.

Original comment by joel.leitch@gmail.com on 12 Apr 2011 at 5:31

• Changed state: Fixed

[GoogleCodeExporter]

Thanks for the fix.

Are there instructions for doing a local snapshot build anywhere?

I was hoping to lift a suitable artefact from gson CI, but 
http://continuousbuild.dyndns.org:8080/job/gson/ seems rather sad at the moment.

Original comment by t.denley on 12 Apr 2011 at 7:13

[GoogleCodeExporter]

We are planning to push a new version of Gson today. Can you wait another day 
for the public release?

Original comment by joel.leitch@gmail.com on 12 Apr 2011 at 9:36

[GoogleCodeExporter]

Sure, no rush.

I was under the impression that this fix hadn't made it into 1.7 though. Am I 
mistaken?

Original comment by t.denley on 12 Apr 2011 at 10:09

[GoogleCodeExporter]

The 1.7 push went out earlier today that contains this fix. Enjoy!

Original comment by joel.leitch@gmail.com on 13 Apr 2011 at 7:16

[GoogleCodeExporter]

Fantastic! Thanks.

Original comment by t.denley on 13 Apr 2011 at 8:03