[java] Deserialize Java 8 LocalDateTime with JacksonMapper

I have read several questions with answers here in SO concerning serialization and deserialization between java.time.LocalDateTime and JSON property but I can't seem to get it working.

I have managed to configure my Spring Boot Application to return the dates in the format I desire (YYY-MM-dd HH:mm) but I have problems accepting values in this format in JSON.

These are all the things I have done so far:

Added maven dependency for jsr310:

<dependency>
    <groupId>com.fasterxml.jackson.datatype</groupId>
    <artifactId>jackson-datatype-jsr310</artifactId>
</dependency>

Specified jsr310 in my main class:

@EntityScan(basePackageClasses = { App.class, Jsr310JpaConverters.class })

Disabled serialization as timestamps in application.properties:

spring.jackson.serialization.write_dates_as_timestamps=false

And this is my entity mapping for datetime:

@Column(name = "start_date")
@DateTimeFormat(iso = DateTimeFormat.ISO.TIME)
@JsonFormat(pattern = "YYYY-MM-dd HH:mm")
private LocalDateTime startDate;

In my database, I store this date as TIMESTAMP in the following format: 2016-12-01T23:00:00+00:00.

If I access this entity via my controller, it returns the JSON with correct startDate format. When I try to post it and deserialize it though, using YYYY-MM-dd HH:mm format, I get the following exception:

{
  "timestamp": "2016-10-30T14:22:25.285+0000",
  "status": 400,
  "error": "Bad Request",
  "exception": "org.springframework.http.converter.HttpMessageNotReadableException",
  "message": "Could not read document: Can not deserialize value of type java.time.LocalDateTime from String \"2017-01-01 20:00\": Text '2017-01-01 20:00' could not be parsed: Unable to obtain LocalDateTime from TemporalAccessor: {MonthOfYear=1, WeekBasedYear[WeekFields[SUNDAY,1]]=2017, DayOfMonth=1},ISO resolved to 20:00 of type java.time.format.Parsed\n at [Source: java.io.PushbackInputStream@679a734d; line: 6, column: 16] (through reference chain: com.gigsterous.api.model.Event[\"startDate\"]); nested exception is com.fasterxml.jackson.databind.exc.InvalidFormatException: Can not deserialize value of type java.time.LocalDateTime from String \"2017-01-01 20:00\": Text '2017-01-01 20:00' could not be parsed: Unable to obtain LocalDateTime from TemporalAccessor: {MonthOfYear=1, WeekBasedYear[WeekFields[SUNDAY,1]]=2017, DayOfMonth=1},ISO resolved to 20:00 of type java.time.format.Parsed\n at [Source: java.io.PushbackInputStream@679a734d; line: 6, column: 16] (through reference chain: com.gigsterous.api.model.Event[\"startDate\"])",
  "path": "/api/events"
}

I know that there are many answers concerning this topic but following them and trying for couple of hours did not help me to figure out what am I doing wrong so I would be glad if someone could point out to me what am I missing. Thanks for any input on this!

EDIT: These are all the classes involved in the process:

Repository:

@Repository
public interface EventRepository extends PagingAndSortingRepository<Event, Long> {
}

Controller:

@RequestMapping(method = RequestMethod.POST, consumes = MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity<Event> createEvent(@RequestBody Event event) {
        return new ResponseEntity<>(eventRepo.save(event), HttpStatus.CREATED);
}

My JSON request payalod:

{
  "name": "Test",
  "startDate": "2017-01-01 20:00"
}

Event:

@Entity
@Table(name = "events")
@Getter
@Setter
public class Event {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "event_id")
    private long id;

    @Column(name = "name")
    private String name;

    @Column(name = "start_date")
    @DateTimeFormat(iso = DateTimeFormat.ISO.TIME)
    @JsonFormat(pattern = "YYYY-MM-dd HH:mm")
    private LocalDateTime startDate;
}

This worked for me :

import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.format.annotation.DateTimeFormat.ISO;

@Column(name="end_date", nullable = false)
@DateTimeFormat(iso = ISO.DATE_TIME)
@JsonFormat(pattern = "yyyy-MM-dd HH:mm")
private LocalDateTime endDate;

You can implement your JsonSerializer

See:

That your propertie in bean

@JsonProperty("start_date")
@JsonFormat("YYYY-MM-dd HH:mm")
@JsonSerialize(using = DateSerializer.class)
private Date startDate;

That way implement your custom class

public class DateSerializer extends JsonSerializer<Date> implements ContextualSerializer<Date> {

    private final String format;

    private DateSerializer(final String format) {
        this.format = format;
    }

    public DateSerializer() {
        this.format = null;
    }

    @Override
    public void serialize(final Date value, final JsonGenerator jgen, final SerializerProvider provider) throws IOException {
        jgen.writeString(new SimpleDateFormat(format).format(value));
    }

    @Override
    public JsonSerializer<Date> createContextual(final SerializationConfig serializationConfig, final BeanProperty beanProperty) throws JsonMappingException {
        final AnnotatedElement annotated = beanProperty.getMember().getAnnotated();
        return new DateSerializer(annotated.getAnnotation(JsonFormat.class).value());
    }

}

Try this after post result for us.

There are two problems with your code:

1. Use of wrong type

LocalDateTime does not support timezone. Given below is an overview of java.time types and you can see that the type which matches with your date-time string, 2016-12-01T23:00:00+00:00 is OffsetDateTime because it has a zone offset of +00:00.

Change your declaration as follows:

private OffsetDateTime startDate;

2. Use of wrong format

There are two problems with the format:

• You need to use y (year-of-era ) instead of Y (week-based-year). Check this discussion to learn more about it. In fact, I recommend you use u (year) instead of y (year-of-era ). Check this answer for more details on it.
• You need to use XXX or ZZZZZ for the offset part i.e. your format should be uuuu-MM-dd'T'HH:m:ssXXX.

Check the documentation page of DateTimeFormatter for more details about these symbols/formats.

Demo:

import java.time.OffsetDateTime;
import java.time.format.DateTimeFormatter;

public class Main {
    public static void main(String[] args) {
        String strDateTime = "2019-10-21T13:00:00+02:00";
        DateTimeFormatter dtf = DateTimeFormatter.ofPattern("uuuu-MM-dd'T'HH:m:ssXXX");
        OffsetDateTime odt = OffsetDateTime.parse(strDateTime, dtf);
        System.out.println(odt);
    }
}

Output:

2019-10-21T13:00+02:00

Learn more about the modern date-time API from Trail: Date Time.

UPDATE:

Change to:

@Column(name = "start_date")
@DateTimeFormat(pattern = "yyyy-MM-dd HH:mm", iso = ISO.DATE_TIME)
@JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd HH:mm")
private LocalDateTime startDate;

JSON request:

{
 "startDate":"2019-04-02 11:45"
}

You used wrong letter case for year in line:

@JsonFormat(pattern = "YYYY-MM-dd HH:mm")

Should be:

@JsonFormat(pattern = "yyyy-MM-dd HH:mm")

With this change everything is working as expected.

This worked for me:

 @JsonFormat(pattern = "yyyy-MM-dd'T'HH:mm:ss.SSSZ", shape = JsonFormat.Shape.STRING)
 private LocalDateTime startDate;