Behavior change to bean discovery in modules with empty beans.xml file

In CDI prior to CDI 4.0, JAR and WAR archives which contain a beans.xml deployment descriptor file with no <beans> element are considered explicit bean archives. In these archives, CDI can manage and inject any bean, except those annotated with @Vetoed.

In CDI 4.0, these archives are considered implicit bean archives. In implicit bean archives, CDI can only manage and inject beans annotated with a bean-defining annotation.

To mark an archive as an explicit bean archive and restore the bean discovery behavior of the previous release, provide a beans element in the file and specify both the version attribute (set to 1.1 or newer) and the bean-discovery-mode="all" attribute, on the beans element:

<beans xmlns="https://jakarta.ee/xml/ns/jakartaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="https://jakarta.ee/xml/ns/jakartaee https://jakarta.ee/xml/ns/jakartaee/beans_4_0.xsd"
    bean-discovery-mode="all"
    version="4.0">
</beans>

For more Jakarta 10 migration information, see Differences between Jakarta Contexts and Dependency Injection 4.0 and 3.0.