Jersey + Jackson JSON date format serialization - how to change the format or use custom JacksonJsonProvider
jackson, java, jax-rs, jersey, serialization
Solution
For what it's worth, that number is standard Java timestamp (used by JDK classes); Unix stores seconds, Java milliseconds, which is why it's bit larger value.
I would hope there are some documents as to how to inject ObjectMapper into Jersey (it should follow the usual way to inject provided object). But alternatively you could override JacksonJaxRsProvider to specify/configure ObjectMapper and register that; this is what Jersey itself does, and there are multiple ways to do it.
Problem
I am using Jersey + Jackson to provide REST JSON services layer for my application. The problem I have is that the default Date serialization format looks like that: ``` "CreationDate":1292236718456 ``` At first I thought it is a UNIX timestamp... but it is too long for that. My client-side JS library has problems deserializing this format (it supports a bunch of different date formats but not this one I suppose). I want to change the format so that it can be consumable by my library (to ISO for example). How do I do that... I found a piece of code that could help but... where do I put it as I don't control the Jackson serializer instantiation (Jersey does)? ``` objectMapper.configure( SerializationConfig.Feature.WRITE_DATES_AS_TIMESTAMPS, false); ``` I also found this code for custom `JacksonJsonProvider` - the question is .. how do I make all my POJO classes use it? ``` @Provider public class MessageBodyWriterJSON extends JacksonJsonProvider { private static final String DF = "yyyy-MM-dd’T'HH:mm:ss.SSSZ"; @Override public boolean isWriteable(Class arg0, Type arg1, Annotation[] arg2, MediaType arg3) { return super.isWriteable(arg0, arg1, arg2, arg3); } @Override public void writeTo(Object target, Class arg1, Type arg2, Annotation[] arg3, MediaType arg4, MultivaluedMap arg5, OutputStream outputStream) throws IOException, WebApplicationException { SimpleDateFormat sdf=new SimpleDateFormat(DF); ObjectMapper om = new ObjectMapper(); om.getDeserializationConfig().setDateFormat(sdf); om.getSerializationConfig().setDateFormat(sdf); try { om.writeValue(outputStream, target); } catch (JsonGenerationException e) { throw e; } catch (JsonMappingException e) { throw e; } catch (IOException e) { throw e; } } } ```