fix: honor required fields in jackson @JsonProperty annotations

[elagerho]

This PR honors required openapi fields when generating Jackson's @JsonProperty annotations. It will appropriately cause deserialization to throw if incoming JSON is not conforming. Adjacent @JsonBProperty annotations do already honor the required fields.

Tested by local override of the templates using the Java with Jackson generator. Issue here. It might be considered a breaking change, since Jackson deserialization will throw. For now filing against master.

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[elagerho]

Is Circle a bit flaky maybe? Seems like all nodes do the same thing.

[elagerho]

Pinging the Java committee. Would love your input on this. @bbdouglas (2017/07) @sreeshas (2017/08) @jfiala (2017/08) @lukoyanov (2017/09) @cbornet (2017/09) @jeff9finger (2018/01) @karismann (2019/03) @Zomzog (2019/04) @lwlee2608 (2019/10) @martin-mfg (2023/08)

[wing328]

thanks for the pr.

i think we also need to handle the case in which the required field is nullable. ({{#isNullable}} ... {{/isNullable}} in mustache template)

[Binnette]

Hi @elagerho, thanks for this PR! 👍

To rephrase, if my field is required in my OpenApi contract (required: ["my_field"] in its parent object), then the Java property in the generated file will be annotated with @JsonProperty(required=true).

Is that correct? If so, I'm very interested in this PR! 😃

Ah! it seems the answer is yes. As stand in your issue report #21060

[wing328]

merged with #21876 with support for nullable as well.