如何使用Jackson反序列化JS日期？

Question

I'm getting a date string from ExtJS in the format:

"2011-04-08T09:00:00"

when i try to deserialize this date, it changes the timezone to Indian Standard Time (adds +5:30 to the time) . This is how i'm deserializing the date:

SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
getObjectMapper().getDeserializationConfig().setDateFormat(dateFormat);

Doing this also doesn't change the timezone. I still get the date in IST:

SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
dateFormat.setTimeZone(TimeZone.getTimeZone("GMT"));
getObjectMapper().getDeserializationConfig().setDateFormat(dateFormat);

How do I deserialize the date in the way in which it is coming without the hassles of Timezone?

Answer 1

I found a work around but with this I'll need to annotate each date's setter throughout the project. Is there a way in which I can specify the format while creating the ObjectMapper?

Here's what I did:

public class CustomJsonDateDeserializer extends JsonDeserializer<Date>
{
    @Override
    public Date deserialize(JsonParser jsonParser,
            DeserializationContext deserializationContext) throws IOException, JsonProcessingException {

        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
        String date = jsonParser.getText();
        try {
            return format.parse(date);
        } catch (ParseException e) {
            throw new RuntimeException(e);
        }

    }

}

And annotated each Date field's setter method with this:

@JsonDeserialize(using = CustomJsonDateDeserializer.class)

Answer 2

This works for me - i am using jackson 2.0.4

ObjectMapper objectMapper = new ObjectMapper();
final DateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
objectMapper.setDateFormat(df);

Answer 3

There is a good blog about this topic: http://www.baeldung.com/jackson-serialize-dates Use @JsonFormat looks the most simple way.

public class Event {
    public String name;

    @JsonFormat
      (shape = JsonFormat.Shape.STRING, pattern = "dd-MM-yyyy hh:mm:ss")
    public Date eventDate;
}

Answer 4

In addition to Varun Achar's answer , this is the Java 8 variant I came up with, that uses java.time.LocalDate and ZonedDateTime instead of the old java.util.Date classes.

public class LocalDateDeserializer extends JsonDeserializer<LocalDate> {

    @Override
    public LocalDate deserialize(JsonParser jsonparser, DeserializationContext deserializationcontext) throws IOException {

        String string = jsonparser.getText();

        if(string.length() > 20) {
            ZonedDateTime zonedDateTime = ZonedDateTime.parse(string);
            return zonedDateTime.toLocalDate();
        }

        return LocalDate.parse(string);
    }
  }

Answer 5

@JsonFormat only work for standard format supported by the jackson version that you are using.

Ex :- compatible with any of standard forms ("yyyy-MM-dd'T'HH:mm:ss.SSSZ", "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", "EEE, dd MMM yyyy HH:mm:ss zzz", "yyyy-MM-dd")) for jackson 2.8.6