Historically, the Spring Framework first had support for repeatable
annotations based on convention and later added explicit support for
Java 8's @Repeatable facility. Consequently, the support for both
types of repeatable annotations has grown a bit intertwined over the
years. However, modern Java applications typically make use of
@Repeatable, and convention-based repeatable annotations have become
more of a niche.
The RepeatableContainers API supports both types of repeatable
annotations with @Repeatable support being the default. However,
RepeatableContainers.of() makes it very easy to enable support for
convention-based repeatable annotations while accidentally disabling
support for @Repeatable, which can lead to subtle bugs – for example,
if convention-based annotations are combined with @Repeatable
annotations. In addition, it is not readily clear how to combine
@Repeatable support with convention-based repeatable annotations.
In light of the above, this commit revises the RepeatableContainers API
to better guide developers to use @Repeatable support for almost all
use cases while still supporting convention-based repeatable
annotations for special use cases.
Specifically:
- RepeatableContainers.of() is now deprecated in favor of the new
RepeatableContainers.explicitRepeatable() method.
- RepeatableContainers.and() is now deprecated in favor of the new
RepeatableContainers.plus() method which declares the repeatable and
container arguments in the same order as the rest of Spring
Framework's repeated annotation APIs.
For example, instead of the following confusing mixture of
repeatable/container and container/repeatable:
RepeatableContainers.of(A.class, A.Container.class)
.and(B.Container.class, B.class)
Developers are now be able to use:
RepeatableContainers.explicitRepeatable(A.class, A.Container.class)
.plus(B.class, B.Container.class)
This commit also overhauls the Javadoc for RepeatableContainers and
explicitly points out that the following is the recommended approach to
support convention-based repeatable annotations while retaining support
for @Repeatable.
RepeatableContainers.standardRepeatables()
.plus(MyRepeatable1.class, MyContainer1.class)
.plus(MyRepeatable2.class, MyContainer2.class)
See gh-20279
Closes gh-34637
274a689a10