Jackson's @JsonProperty in @JsonCreator methods should not affect Kotlin class properties.

Java version: 1.8.0_144 Kotlin version: 1.1.51

Given a Java class:

public class User {
    private final Long id;
    private final String name;

    @JsonCreator
    public User(
            @JsonProperty("user_id")
                    Long id,
            @JsonProperty("user_name")
                    String name) {
        this.id = id;
        this.name = name;
    }
   // Getters
}

one is able to deserialize it from json

{"user_id": 1, "user_name": "john"}

and serialize it to

{"id":1, "name": "john"}

However, given the equivalent Kotlin class

class User
@JsonCreator constructor(
        @JsonProperty("user_id")
        id: Long,
        @JsonProperty("user_name")
        name: String) {
    val id = id
    val name = name
}

the serialization result becomes

{"user_id": 1, "user_name": "john"}

(deserialization still works as-is though).

Same thing happens with a static @JsonCreator method like

class User(val id: Long, val name: String) {
    companion object {
        @JsonCreator
        @JvmStatic
        fun create(@JsonProperty("user_id")
                   id: Long,

                   @JsonProperty("user_name")
                   name: String): User {
            return User(id, name)
        }
    }
}

The expectation is that the @JsonProperty in the constructor or the static factory method would only be effective in the scope of the method; it shouldn’t affect the properties in the class.

What confuses me more is that why the @JsonProperty annotations in the static @JsonCreator method would affect the properties in the class…

Please fix the inconsistency.

[ghost]

@get:JsonProperty("user_id") Long id works for me.

[cowtowncoder]

@HunterSherms since all annotations for all accessors (getter, setter, field, creator argument) are combined, both serialization and deserialization can be affected. So renaming affects the “whole” logical property, not just one direction.

Whether serialization or deserialization is being performed does affect precedence (priority) of annotations, however. So for deserialization, constructor parameters have highest precedence, followed by setter, then by field. For serialization highest precedence by getter.

Hope this helps.