`InvalidDefinitionException` on classes using `@JacksonXmlElementWrapper` and `@JacksonXmlProperty`

[soc]

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• I searched in the issues and found nothing similar.

Describe the bug

Consider this pattern where serialization to XML is customized for properties of collections ...

public class GroupDto {
  @JacksonXmlElementWrapper(localName = "users")
  @JacksonXmlProperty(localName = "user")
  List<String> users;
  // other fields

  public GroupDto(List<String> users, /* other arguments */) {}

  List<String> getUsers() { return users; }
  // other getters
}

... such that the particular XML fragment looks like this:

<users>
  <user>A</user>
  <user>B</user>
  <user>C</user>
</users>
<!-- other elements -->

This worked on Jackson 2.x, but fails on Jackson 3 with ...

InvalidDefinitionException: Invalid definition for property 'users' (of type `GroupDto`): Could not find creator property with name 'users' (known Creator properties: [user, /* other property names */])

Note the users/user difference in the message.

• Adding a @JsonProperty to the field fails with an error about ambiguous property names instead.
• Changing the argument name in the constructor to the one seemingly expected (user) does not help.

---

There appear to be two workarounds:

1. Adding a no-arg constructor with @JsonCreator (or removing all existing arg-constructors) and setters.
2. Adding @JsonIgnore to the field, and @JsonPropertys to the field's getters and setters.

Both workarounds are undesirable, as they make the class mutable and therefore prevent a migration to a record.

Version Information

Jackson 3.1.2

Reproduction

See code snippet above.

Expected behavior

There should be a way to deserialize types with fields that are annotated with @JacksonXmlElementWrapper and @JacksonXmlProperty, without making the class mutable (which prevents the use of records altogether).

[cowtowncoder]

Fixed in 3.x for 3.2.0 (originally to address #615)

[soc]

Thank you @cowtowncoder, I will test 3.2.0 when available and report back!

[cowtowncoder]

You may be able to try 3.2.0-SNAPSHOT as well.