Serializing Joda DateTime with Jackson and Spring

Question

I am having problems consistently serializing and deserializing a Joda DateTime from java to json and back again using Spring Boot and Jackson-databind 2.5.2. My pom.xml looks like this.

    <dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.5.2</version>
</dependency>

<dependency>
    <groupId>com.fasterxml.jackson.datatype</groupId>
    <artifactId>jackson-datatype-joda</artifactId>
    <version>2.5.2</version>
</dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
    <version>1.2.1.RELEASE</version>
</dependency>

When I serialize the DateTime object I get an integer representing the DateTime. Not what I expected actually, but fine. BUT when I go to save my object back I get the following error...

Failed to convert property value of type 'java.lang.String' to required type 'org.joda.time.DateTime' for property 'endTime';
nested exception is org.springframework.core.convert.ConversionFailedException: Failed to convert from type java.lang.String to type org.joda.time.DateTime for value '1428600998511'

For some reason it is serializing it to an integer but then deserializing it as if it's a string, which it is not. I also tried setting the endTime = new Date(intValue) before calling the rest service and that also failed trying to convert a string like 'Tue Apr 28 2015 00:00:00 GMT-0700 (PDT)' to a DateTime.

What am I doing wrong?

UPDATE:

Here is the JSON that I GET and that I try to immediately POST right back.

{
    id: 4,
    username: "",
    name: "eau",
    email: "aoue",
    verbatimLocation: null,
    latitude: null,
    longitude: null,
    startTime:null,
    endTime: 1429034332312,
    description: "ueoa",
    media: [ ],
    timeSubmitted: 1428600998000,
    status: null,
    submissionid: null
}

Answer 1

For a more re-usable mechanism, you can create a JsonSerializer:

/**
 * When passing JSON around, it's good to use a standard text representation of
 * the date, rather than the full details of a Joda DateTime object. Therefore,
 * this will serialize the value to the ISO-8601 standard:
 * <pre>yyyy-MM-dd'T'HH:mm:ss.SSSZ</pre>
 * This can then be parsed by a JavaScript library such as moment.js.
 */
public class JsonJodaDateTimeSerializer extends JsonSerializer<DateTime> {

    private static DateTimeFormatter formatter = ISODateTimeFormat.dateTime();

    @Override
    public void serialize(DateTime value, JsonGenerator gen, SerializerProvider arg2)
            throws IOException, JsonProcessingException {

        gen.writeString(formatter.print(value));
    }

}

Then you can annotate your get methods with:

@JsonSerialize(using = JsonJodaDateTimeSerializer.class)

This gives you consistent formatting throughout your application, without repeating text patterns everywhere. It's also timezone aware.