@Target({TYPE, METHOD, PARAMETER, FIELD}) @Retention(RUNTIME) @Documented @Qualifier

This is a Java annotation used to indicate that a given type, method, parameter, or field is a qualifier. Qualifiers are used to distinguish between different implementations of the same interface or class.

The @Target annotation specifies where this annotation can be used. In this case, it can be used on types, methods, parameters, and fields.

The @Retention annotation specifies how long this annotation should be retained for. In this case, it should be retained at runtime.

The @Documented annotation indicates that this annotation should be included in the Javadoc for the annotated element.

Overall, this annotation is used to mark a specific implementation of an interface or class, and to indicate that it should be used in preference to other implementations in certain situations.