How to change Duration Format in JSON Java

Question

I have a class with some field

public class SomeClass {
   private Duration discussionTime;
}

When i try to send this class to frontend using @RestController in Spring, i see that answer:

"discussionTime": {
                "seconds": 7,
                "zero": false,
                "negative": false,
                "nano": 72000000,
                "units": [
                    "SECONDS",
                    "NANOS"
                ]
            }

Is there ways to set format of answer to "discussionTime": 7 ?

Either through custom mapping to a new object, or by creating your own serializer: https://stackoverflow.com/a/27952473/2082699 But if you only want the seconds, might be best to just create a new object you serialize instead of messing with the Duration. — Tom Cools, Apr 16 '20 at 07:30
could you upvote my answer in this case, so others can see this as well? — Tom Cools, Apr 16 '20 at 07:57

score 2 · Answer 1 · answered Apr 16 '20 at 07:56

There are two ways you can do this:

custom mapping to a new object (instead of returning a Duration)
by creating your own serializer: serialize/deserialize java 8 java.time with Jackson JSON mapper

But if you only want the seconds, might be best to just create a new object you serialize instead of messing with the Duration.

Balázs Németh · Answer 2 · 2020-04-16T08:14:45.827

An option could be to use a MixIn.

Also JavaTimeModule could help you.

Depending on your use case you can create your own serializer as suggested by others or go for a more generic solution if you have to do this in multiple places.

Or maybe:

public class SomeClass {
  private Duration discussionTime;

  @JsonProperty("discussionTime")
  public long getDiscussionTimeSeconds() {
      return discussionTime.getSeconds();
  }
}

How to change Duration Format in JSON Java

2 Answers2