Convert link with RFC5988 additional attributes

[jtwalraven]

I noticed that the deserialization in the Jackson2HalModule was not working with the additional RFC5988 attributes added in PR #567 . This adds two tests for converting from Json.

Unfortunately, I am having trouble getting media to work. It does not seem to be converted properly using the json parser. I will continue looking into this, but would appreciate one of the maintainers looking it over.

Also, note: I would use one constructor for the link in the deserialization, but it was mentioned in #567 to use Lambok notation. Currently, the constructor containing the attributes is protected and cannot be accessed from the Jackson2HalModule.

[pivotal-issuemaster]

@jtwalraven Please sign the Contributor License Agreement!

Click here to manually synchronize the status of this Pull Request.

See the FAQ for frequently asked questions.

[pivotal-issuemaster]

@jtwalraven Thank you for signing the Contributor License Agreement!

[jtwalraven]

This also needs "profile" attribute from: #679

[gregturn]

For starters, "media" is not an attribute in the HAL spec. In general, it can be included as part of RFC5988, meaning it may appear when a Link is rendered as an HTTP header, but it's not for serialization into a HAL document. That's why it's explicitly excluded in org.springframework.hateoas.hal.LInkMixin.

[gregturn]

Thanks @jtwalraven!

I took your PR, polished it a little and fixed the test cases.

Resolved at ba1dae3.

[jtwalraven]

@gregturn That makes a lot of sense. You're welcome and thanks for explaining/fixing!