CODEWITHSUNDEEP
javajsongoogle-app-enginegoogle-cloud-endpoints
Pokuri
Pokuri

Reputation: 3082

google cloud endpoints returning java long as string in JSON

I am using google app engine latest version 1.9.30 and I define my cloud endpoint as follows

@Api(name="app", version="v1", transformers={EndpointDateTransformer.class})
public class MyEndpoints {

    @ApiMethod(name="dummy", path="dummy", httpMethod=HttpMethod.GET)
    public Map<String, Object> dummy(){
        Map<String, Object> dummy = Maps.newHashMap();
        dummy.put("date", DateUtil.getCurrentTimestamp());
        dummy.put("number", 5L);
        return dummy;
    }

}

here EndpointDateTransformer converts Date to Long value and the JSON response from endpoint is 

{
    "number": "5",
    "date": "1452751174672"
}

But if I change that 5L to 5 then I see JSON response as

{
    "number": 5,
    "date": "1452751174672"
}

Why cloud endpoints converting Long values as string in JSON. When I was working on old app engine versions 1.9.19 it used to work. Long rendered as long on JSON as well. Am I missing anything here?

Upvotes: 4

Views: 726

Answers (1)

Igor Artamonov
Igor Artamonov

Reputation: 35951

JSON is JavaScript Object Notation, it's a valid Javascript actually. So it should follow javascript standards.

Javascript's Number is 54 bit number, from -(2^53 - 1) to (2^53 - 1). But Java's long is 64 bit number, from -2^63 to 2^63-1.

See difference: 

Java Long Max         = 9223372036854775807
Javascript Number Max = 9007199254740992

You simply cannot convert Java Long to Javascript Number because it doesn't work for all values. So a string representation is used instead.

You have two possible solutions:

Or if you really want Date, it's better to format it as yyyy-MM-dd\'T\'HH:mm:ss within UTC timezone. It's compatible with Javascript date format.

Specs:

Upvotes: 6

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