Introduce 'value' alias for 'attribute' in @AliasFor [SPR-13289]

[spring-projects-issues]

Sam Brannen opened SPR-13289 and commented

Status Quo

#16137 introduced support for annotation attribute aliases via @AliasFor. For example, this support allows @ContextConfiguration from the spring-test module to declare aliases as follows:

public @interface ContextConfiguration {

     @AliasFor(attribute = "locations")
     String[] value() default {};

     @AliasFor(attribute = "value")
     String[] locations() default {};

    // ...
}

For greater readability, it would be beneficial to be able to omit the attribute = "..." declaration by providing a value alias for attribute.

Deliverables

1. Introduce a value alias for attribute in @AliasFor.

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Affects: 4.2 RC1

Issue Links:

• Introduce unified support for declaring and looking up annotation attribute aliases [SPR-11512] #16137 Introduce unified support for declaring and looking up annotation attribute aliases ("depends on")

Referenced from: commits 7252920, 1c8ac2b

[spring-projects-issues]

Sam Brannen commented

Implemented in GitHub commit 7252920:

Introduce 'value' alias for 'attribute' in @AliasFor

#16137 introduced support for annotation attribute aliases via @AliasFor, requiring the explicit declaration of the attribute attribute. However, for aliases within an annotation, this explicit declaration is unnecessary.

This commit improves the readability of alias pairs declared within an annotation by introducing a value attribute in @AliasFor that is an alias for the existing attribute attribute. This allows annotations such as @ContextConfiguration from the spring-test module to declare aliases as follows.

public @interface ContextConfiguration {

     @AliasFor("locations")
     String[] value() default {};

     @AliasFor("value")
     String[] locations() default {};

    // ...
}