Dropwizard GET the Timestamp using GET returns epoch

[Shammi Syan]

Hi,

I have stored the Timestamp in H2 database where is stored in " dd/mm/yyyy hh:mm:ss".

But when i retrieve it using a GET from my DTO with java.sql.Timestamp field ,

the response shows me an EPOCH  value.

Is this the right behvaiour? If yes, how to get a " dd/mm/yyyy hh:mm:ss". as Response ?

Thanks

Syan

[Ryan Kennedy]

Are you returning the Timestamp from your resource method? i.e.

@GET

public Timestamp getTheTime() {

    …

}

And what MIME type are you sending back? Do you have an @Produces annotation anywhere? All of those things affect how the response is rendered. Without knowing those it's going to be difficult to help you.

If you don't know how JAX-RS generates response bodies from method return values, the Jersey documentation is pretty good at explaining it:

https://jersey.java.net/documentation/latest/message-body-workers.html#d0e6765

Ryan

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[Shammi Syan]

hi Ryan,

My DTO is like this

========================

@Entity

@Table(name = "Person")

@NamedQueries({

        @NamedQuery(

                name = "com.syan.dto.Person.findPerson",

                query = "SELECT pv FROM Person pv WHERE id = :id"

        )

public class Person

{

@Column(name = "id", nullable = false)

private Long id;

@Column(name = "visitDate", nullable = false)

private Timestamp visitDate;

public Long getId() {

    return id;

}

public void setId(Long id) {

    this.id = id;

}

@JsonProperty

public Timestamp getVisitDate() {

    return visitDate;

}

@JsonProperty

public void setVisitDate(Timestamp visitDate) {

    this.visitDate = visitDate;

}

}

PersonDAO

========================

 public List<Person> findPerson(long id) {

            return list(namedQuery("com.truecaller.rest.dto.findPerson")

               .setParameter("id", id)                 

}

PersonResource

==========================

@Path("/person")

@Produces(MediaType.APPLICATION_JSON)

public class PersonResource {

  private final PersonDAO personDAO;

@GET

@Path("/{Id}")

@Produces(MediaType.APPLICATION_JSON)

@UnitOfWork

public List<Person> listPerson(

@PathParam("idd") LongParam id) {

Long userId = id.get();

return personDAO.findPerson(userId);

}

}

Thanks

Syan

[Ryan Kennedy]

You're running into Jackson's default date handling, which is to serialize as epoch time. See:

    http://wiki.fasterxml.com/JacksonFAQDateHandling

Adding the following to the run() method of your Application subclass will switch to ISO-8601 dates:

    environment.getObjectMapper().configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);

If you want something other than that format (I'd recommend ISO-8601 in most cases), the Jackson FAQ linked above has instructions on how to use your own date format.

On an unrelated note, I saw something in your DTO and DAO that I thought I'd point out. You're using a NamedQuery:

    SELECT pv FROM Person pv WHERE id = :id

The simple queries to fetch an object by it's ID can be handled in the DAO without needing the named query:

    public class PersonDAO extends AbstractDAO<Person> {

        public Optional<Person> findById(long id) {

            return Optional.ofNullable(get(id));

        }

    }

You may need to add the @Id annotation to the "id" field on the Person class for this to work, but you should probably be doing that anyway if it's truly the unique ID for the user. I believe that also influences Hibernate caching since it can cache by the primary key.

Your version of PersonDAO is also returning a List<Person>. Is it really possible for multiple Persons to have the same ID in your schema? If so, maybe "id" isn't the proper name for that attribute. If not, you don't need to use list(). Switch to get() and pass it the ID. Then you can get rid of the NamedQuery altogether.

Ryan

[Shammi Syan]

Thanks Ryan

It is working fine after using 

environment.getObjectMapper().configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);

[Tatu Saloranta]

Something that may be of interest as well is use of @JacksonFeatures annotation, applicable to resource methods.

You can also do:

public class Resource {

   @GET // and other jax-rs stuff

   @JacksonFeatures(serializationDisable={ SerializationFeature.WRITE_DATES_AS_TIMESTAMPS })

   public Stuff getStuff() { ... }

with this, you can enable/disable individual SerializationFeatures and DeserializationFeatures on per-resource basis.

-+ Tatu +-