Align file headers on other Hibernate projects

[yrodiere]

Other Hibernate projects (ORM, Search, Validator) use this header:

/*
* SPDX-License-Identifier: Apache-2.0
* Copyright Red Hat Inc. and Hibernate Authors
*/

Hibernate Reactive uses that:

/* Hibernate, Relational Persistence for Idiomatic Java
 *
 * SPDX-License-Identifier: Apache-2.0
 * Copyright: Red Hat Inc. and Hibernate Authors
 */

Let's align Hibernate Reactive on other projects, and maybe add some check to be sure it's applied everywhere? It seems missing from this file, for example:

https://github.com/hibernate/hibernate-reactive/blob/main/hibernate-reactive-core/src/main/java/org/hibernate/reactive/adaptor/package-info.java

See also hibernate/hibernate.org#312 (comment)

[DavideD]

https://github.com/hibernate/hibernate-reactive/blob/main/hibernate-reactive-core/src/main/java/org/hibernate/reactive/adaptor/package-info.java

It seems to be a bug in spotless: diffplug/spotless#532
Is it really necessary to add a license to the package-info.java?

[yrodiere]

Ah, so there is a check currently. Good.

None of these headers are necessary, depending who you ask. It's mainly about consistency, like our code style, at this point.
So as long as we have a check in general, it's fine.

Still, there's the matter of using the same headers as other projects :) Ultimately.

[DavideD]

Ah, so there is a check currently. Good.

Yes, of course :) It also replaces the header automatically at compile time, so you don't see any error.
I think the workaround suggested in the spotless issue works, it just requires a javadoc in the package-info (and we have one in all of them except for a test).

I will send a PR tomorrow