Lombok `@Builder.Default` no longer applied during Jackson 3 deserialization

[ditogam]

Lombok @Builder.Default no longer applied during Jackson 3 deserialization

Summary

In Jackson 2.x, Lombok’s @Builder.Default values were automatically preserved during deserialization.
In Jackson 3.x, these defaults are no longer applied, and missing fields now become null.

I would like to understand whether this is an intentional design change or a regression, and what the recommended modern approach is.

---

Example (Jackson 2 behavior)

The following class worked correctly in Jackson 2.x:

@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class DisplayConfigUpdate {
    .........................................
    @Builder.Default
    private Boolean isPrimary = true;
    .........................................
}

If the JSON omitted "isPrimary", Jackson 2 populated isPrimary with the default value true.

---

Jackson 3 behavior

With Jackson 3, the same class results in isPrimary = null when the field is missing from JSON.
The default value defined in the builder is ignored.

The only way I was able to restore the old behavior was to manually override the builder like this:

@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
@JsonDeserialize(builder = DisplayConfigUpdate.class)
public class DisplayConfigUpdate {
    .........................................
    @Builder.Default
    private Boolean isPrimary = true;
    .........................................
    public DisplayConfigUpdate build() {
        if (isPrimary == null) {
            isPrimary = true;
        }
        return this;
    }
}

This works, but it defeats the purpose of Lombok’s builder defaults and adds unnecessary boilerplate.

---

Expected behavior

Jackson 3 should behave like Jackson 2 (unless intentionally changed):

• When a field annotated with @Builder.Default is missing from JSON
• The default value defined in the builder initializer should be assigned during deserialization

---

Actual behavior

• Jackson 3 passes null to the builder for missing fields
• Lombok’s default value is not applied
• The only working solution is manually overriding build() and restoring defaults

---

Questions

1. Is this change intentional in Jackson 3?
2. Should @Builder.Default still work the same way, or is there a new recommended pattern?
3. If this is a regression, can support for Lombok builder defaults be restored?

Thank you.

[cowtowncoder]

Wrong repo: will transfer.

[cowtowncoder]

We do not accept Lombok-based reproductions, will need de-Lombokified reproduction.
It is not really possible to say much about the issue without such reproduction.

[cowtowncoder]

NOTE: it seems likely that Lombok is using "wrong" @JsonDeserialize annotation: since this annotation is part of jackson-databind artifact -- and not shared jackson-annotations -- it needs to be Jackson 3.x (tools.jackson.databind.annotations.JsonDeserialize or such) not 2.x.

If so, this is something for Lombok to handle.