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  1. CDI Specification Issues
  2. CDI-484

Provide forwarding implementations of SPI interfaces


    • Icon: Feature Request Feature Request
    • Resolution: Duplicate
    • Icon: Major Major
    • None
    • 1.2.Final
    • Portable Extensions
    • None

      The decorator design pattern is commonly used in CDI extensions to modify existing metadata by wrapping it with a wrapper implementation that overrides certain method. This can be done in the following callbacks: ProcessAnnotatedType, ProcessProducer, ProcessInjectionTarget, ProcessInjectionPoint and ProcessBeanAttributes.

      In order to do this it is often very convenient to have a forwarding implementation available, e.g.:

          void wrap(@Observes ProcessAnnotatedType<Foo> event) {
              final AnnotatedType<Foo> delegate = event.getAnnotatedType();
              event.setAnnotatedType(new ForwardingAnnotatedType<Foo>(delegate) {
                  public <A extends Annotation> A getAnnotation(Class<A> annotationType) {
                      return null;
                  public Set<Annotation> getAnnotations() {
                      return Collections.emptySet();
                  public boolean isAnnotationPresent(Class<? extends Annotation> annotationType) {
                      return false;

      We should consider providing these utility forwarding implementations as part of the CDI API. This is similar to e.g. Servlet specification doing this for their decorable APIs (http://tomcat.apache.org/tomcat-5.5-doc/servletapi/javax/servlet/http/HttpServletRequestWrapper.html)

            Unassigned Unassigned
            rhn-engineering-jharting Jozef Hartinger
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