Retrofit Date Converter

Question

I have a WCF Service that returns a List of objects to an Android app. One of the properties is a DateTime property. The return format is JSON and I am getting the date in this format /Date(1441117247253+0200)/ on the Android side. I am using com.squareup.retrofit:retrofit:1.9.0 to get the data from my service.

I have no clue how to use Retrofit to create a the string date into a Date object. I had a look at this http://square.github.io/retrofit/ under the Custom Converters section, but do not know how to go further. This is what I've tried but I do not know how to implement the converter class.

creating the restAdapter like so:

restAdapter = new RestAdapter.Builder()
                .setConverter(new DotNetDateConverter())
                .setLogLevel(RestAdapter.LogLevel.FULL)
                .setEndpoint(API).build();

and the DotNetDateConverter Class which I do not know how to implement further:

public class DotNetDateConverter implements Converter
{
    @Override
    public Object fromBody(TypedInput body, Type type) throws ConversionException
    {
        return null;
    }

    @Override
    public TypedOutput toBody(Object object)
    {
        return null;
    }
}

there are other fields in the response which are fine, but how do I change the /Date(1441117247253+0200)/ to a proper java.util.Date object? Without the converter I get com.google.gson.JsonSyntaxException:/Date(1441117247253+0200)/ obviously because the string cannot be converter to a date.

Any assistance would greatly be appreciated.

One option is to change your property data type from DateTime to String type on the WCF side and convert the value to string (i.e.: to convert to short date use dateTimeProperty.ToString("d")). And your service operation response should have the correct data format in JSON like "9/2/2015". — Leo Nix, Sep 02 '15 at 20:44
yeah, i thought about that, but then I'll be changing my service to accommodate one client type. the client should really adapt to the service, if you know what I mean. — pjdupreez, Sep 02 '15 at 23:03
Make two objects on the service, one that returns DateTime, another that returns client specific DateTime `dateTimeProperty.ToString("client-supported-format")`. Otherwise are you going to write a low level DateTime converter in javascript just to support the service when you already have the control over it? I wont do that. — DJ', Sep 03 '15 at 09:11

score 3 · Accepted Answer · edited May 23 '17 at 12:19

Ok, so after some digging around, I came across this. My approach was wrong. So I ended up creating a Converter like this:

public class DotNetDateConverter implements JsonDeserializer<Date>
{
    @Override
    public Date deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException
    {
        String s = json.getAsJsonPrimitive().getAsString();
        long l = Long.parseLong(s.substring(s.indexOf("(")+1, s.indexOf("+")));
        Date d = new Date(l);
        return d;
    }
}

I also had to register it like so:

GsonBuilder gsonBuilder = new GsonBuilder();
        gsonBuilder.registerTypeAdapter(Date.class, new DotNetDateConverter());

        restAdapter = new RestAdapter.Builder()
                .setConverter(new GsonConverter(gsonBuilder.create()))
                .setLogLevel(RestAdapter.LogLevel.FULL)
                .setEndpoint(API).build();

I had to change the code a bit to accommodate my specific scenario, that being dates come in as /Date(1441117247253+0200)/ with the time zone. Maybe someone else might find some use for this...

Retrofit Date Converter

1 Answers1