Deserializing empty timestamp fields to `null` value doesn't work (instead becomes "empty", Epoch time)

[silvestr85]

Hi.
From version 2.12.0 deserialization timestamps works in other way.
I have field in model:

    @JacksonXmlProperty(isAttribute = true,localName = "timestampDate")
    @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss")
    private Timestamp timestampDate;

In response i receive something like this:

<PositionsCurrent>
  <PositionsCurrent timestampDate="" />
</PositionsCurrent>

Earlier this assertion worked fine:
Assert.assertNull(response.getData());

On the newest version 2.14 deserialization returns something like this:
Actual :1970-01-01 01:00:00.0

Is it possible to return null again when I try deserialize empty field to Timestamp?

[cowtowncoder]

@silvestr85 Try enabling FromXmlParser.EMPTY_ELEMENT_AS_NULL.

Handling of empty String to "empty" Timestamp is indeed unfortunate and shouldn't occur.

If nothing else works you could alternatively add/override setTimestamp(Timestamp ts) method and look if underlying epoch value (long) is 0L and if so translate instance into null.

ps. which Timestamp class are we talking about? java.sql.Timestamp?

[silvestr85]

I was trying this one FromXmlParser.EMPTY_ELEMENT_AS_NULL but it doesn't work for Timestamp.

Yes, I'm using java.sql.Timestamp

For now I have workaround as my own converter:

public class TimestampConverter extends StdConverter<String, Timestamp> {

    @Override
    public Timestamp convert(final String value) {
        if (value == null || value.equals("")) {
            return null;
        }
        else {
            return Timestamp.valueOf(value);
        }
    }
}

[cowtowncoder]

FWTW, I think this is unfortunately something that happens, as jackson-databind has TimestampDeserializer that indicates that so-called "empty" value is one with instance constructed with timestamp of 0L -- which means January 1st, 1970, UTC (epoch).

So I think work-around indicated makes sense.

[danibs]

I found the solution 🥳

You must set the behaviour of coercionConfigFor:

XmlMapper mapper = new XmlMapper();
mapper.coercionConfigFor( LogicalType.DateTime ).setCoercion( CoercionInputShape.EmptyString, CoercionAction.AsNull );