Deserialize Java 8 LocalDateTime with JacksonMapper

Question

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;
}

Solution 1

The date time you're passing is not an ISO local date time format.

Change to

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

and pass the date string in the format '2011-12-03T10:15:30'.

But if you still want to pass your custom format, you just have to specify the right formatter.

Change to

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

I think your problem is the @DateTimeFormat has no effect at all. As the Jackson is doing the deserialization and it doesn't know anything about spring annotation, and I don't see spring scanning this annotation in the deserialization context.

Alternatively, you can try setting the formatter while registering the Java time module.

LocalDateTimeDeserializer localDateTimeDeserializer = new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm"));
module.addDeserializer(LocalDateTime.class, localDateTimeDeserializer);

Here is the test case with the deseralizer which works fine. Maybe try to get rid of that DateTimeFormat annotation altogether.

@RunWith(JUnit4.class)
public class JacksonLocalDateTimeTest {

    private ObjectMapper objectMapper;

    @Before
    public void init() {
        JavaTimeModule module = new JavaTimeModule();
        LocalDateTimeDeserializer localDateTimeDeserializer =  new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm"));
        module.addDeserializer(LocalDateTime.class, localDateTimeDeserializer);
        objectMapper = Jackson2ObjectMapperBuilder.json()
                .modules(module)
                .featuresToDisable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS)
                .build();
    }

    @Test
    public void test() throws IOException {
        final String json = "{ \"date\": \"2016-11-08 12:00\" }";
        final JsonType instance = objectMapper.readValue(json, JsonType.class);

        assertEquals(LocalDateTime.parse("2016-11-08 12:00",DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm") ), instance.getDate());
    }
}


class JsonType {
    private LocalDateTime date;

    public LocalDateTime getDate() {
        return date;
    }

    public void setDate(LocalDateTime date) {
        this.date = date;
    }
}

Solution 2

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.

Solution 3

This worked for me:

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

Solution 4

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"
}

Solution 5

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.

View more solutions

Comments

[Smajl]

I have an error with this saying I cannot convert from DateTimeFormatter to DateTimeFormat.ISO

[s7vr]

Use the spring equalivent for that formatter. you get the idea right ?

[Smajl]

There is no such class called DateTimeFormatter in Spring. There is only DateTimeFormat (I mentioned it in my question) and i tried both formats with it (2011-12-03T10:15:30 and 2011-12-03 10:15). Neither worked

[s7vr]

okay. There has to be a way to pass the custom pattern to that datetimeformat annotation.

[Smajl]

I sure hope so, that's basically my question. I tried a lot of combinations but nothing worked so far (including @DateTimeFormat(pattern = "YYYY-MM-dd HH:mm"))

[s7vr]

I cant test it now. Can you try @DateTimeFormat(pattern = "yyyy-MM-dd HH:mm")

[Smajl]

I did, see my comment above?

[Smajl]

No, that does not help

[s7vr]

Updated. Please take a look.

[s7vr]

Added a test case with LocalDateTime Deserailizer. Please take a look.

[Smajl]

Thank you for your effort. I made it work and will award bounty once it allows me to

[Maciej Walkowiak]

YYYY is just wrong. Do not overcomplicate your code and change it to yyyy

[ankit]

DateTimeFormatter.ISO_LOCAL_DATE throws compile time error : attribute value must be constant

[pedram bashiri]

I had the same problem as @Smajil , for some reason DateTimeFormat and JsonFormat were not effective (even though JsonFormat is a Jackson annotation). Many ppl suggested implementing my own custom Deserializer but I didn't want to implement one Deserializer for every Json class that I had. This answer saved my day, short sweet and effective

[Spenhouet]

As @ankit said this will not compile. Attribute value must be constant

[ankit]

Please answer my question: stackoverflow.com/questions/52129200/…

[chill appreciator]

It just not compiles

[Christian Meyer]

This is the wrong information. DateTimeFormatter is a different class than DateTimeFormat. DateTimeFormatter only has a select few enum choices, unlike DateTimeFormatter, which has a wide variety. And, by choosing DateTimeFormat.DATE_TIME, you wind up with millis despite the javadoc, which is why I am still looking for a solution.

[Felipe Desiderati]

This part is worng: @DateTimeFormat(iso = DateTimeFormatter.ISO_LOCAL_DATE_TIME)

[Anupam Jain]

yup.. was looking for this thing. For that exact date-time value as mentioned in question "2016-10-30T14:22:25.285+0000", this is the solution which worked for me.

[Xelian]

Thanks this fix my parsing from 2022-02-21T17:57:53.049+0000. But what shape = JsonFormat.Shape.STRING mean?