specifying only timezone in @JsonFormat doesn't serialize ZonedDateTime in specified timezone.

[shankuljain]

For a ZonedDateTime field with timezone(Say ET), annotating this field with @JsonFormat(timezone="UTC") doesn't serialize it in the specified format. If I include the pattern in JsonFormat along with timezone it serializes correctly.

While just specifying timezone while using old Date (from java.util.Date), it serializes in specified timezone. (without specifying pattern)

Jackson versions -
jackson-datatype-jsr : 2.11.0
Jackson Core : 2.11.0
Jackson databind: 2.11.0

Reproducer:

import java.time.ZonedDateTime;

package com.example.demo;

import com.fasterxml.jackson.annotation.JsonFormat;
import java.util.Date;

import java.time.ZonedDateTime;

public class POJO {


    @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss.SSSZ", timezone = "UTC")
    private ZonedDateTime zonedDateTimeWithPatternAndTimeZoneInJsonFormat;

    @JsonFormat(timezone = "UTC")
    private ZonedDateTime zonedDateTimeWithTimeZoneInJsonFormat;

    private ZonedDateTime zonedDateTime;


    @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss.SSSZ", timezone = "UTC")
    private Date oldDateWithTimeZoneAndPatternInJsonFormat;

    @JsonFormat(timezone = "UTC")
    private Date oldDateWithTimeZoneInJsonFormat;

    private Date oldDate;

    //  getters and setters below


}

package com.example.demo;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;

import java.time.*;
import java.util.TimeZone;

package com.example.demo;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.time.*;
import java.time.format.DateTimeFormatter;
import java.util.Calendar;
import java.util.Date;
import java.util.TimeZone;

public class DemoApplication {

    public static void main(String[] args) throws JsonProcessingException {

        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.registerModule(new JavaTimeModule());
        objectMapper.setTimeZone(TimeZone.getDefault());
        objectMapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);

        LocalDateTime ldt = LocalDateTime.of(2020, Month.JUNE.getValue(), 12, 15, 0 , 0);
        ZonedDateTime zdt = ZonedDateTime.of(ldt, ZoneId.of("America/New_York"));
        Date oldDate = Date.from(zdt.toInstant());

        System.out.println("old Date with System's time zone" + oldDate);

        POJO pojo = new POJO();
        pojo.setOldDate(oldDate);
        pojo.setOldDateWithTimeZoneAndPatternInJsonFormat(oldDate);
        pojo.setOldDateWithTimeZoneInJsonFormat(oldDate);

        pojo.setZonedDateTimeWithPatternAndTimeZoneInJsonFormat(zdt);
        pojo.setZonedDateTimeWithTimeZoneInJsonFormat(zdt);
        pojo.setZonedDateTime(zdt);

        System.out.println(objectMapper.writeValueAsString(pojo));

    }


}

Output:

old Date with System's time zone Sat Jun 13 00:30:00 IST 2020

{
    "zonedDateTimeWithPatternAndTimeZoneInJsonFormat": "2020-06-12 19:00:00.000+0000",
    "zonedDateTimeWithTimeZoneInJsonFormat": "2020-06-12T15:00:00-04:00",
    "zonedDateTime": "2020-06-12T15:00:00-04:00",
    "oldDateWithTimeZoneAndPatternInJsonFormat": "2020-06-12 19:00:00.000+0000",
    "oldDateWithTimeZoneInJsonFormat": "2020-06-12T19:00:00.000+00:00",
    "oldDate": "2020-06-13T00:30:00.000+05:30"
}

As you can see in output, for oldDate only specifying timezone serializes in UTC, but not for ZonedDateTime.

[cowtowncoder]

Needs to go to Java8 modules repo where support for Java 8 date/time is added, will transfer.

[cowtowncoder]

Thank you for reporting this; sounds like incomplete handling of @JsonFormat information.

[kupci]

Looks like the same as #175, which was originally for OffsetDateTime, but appeared to impact other date types as well.

[cowtowncoder]

@kupci Thanks, that makes sense.

[cowtowncoder]

I think this is effectively duplicate of #175, closing.