InstallingDynamicProducers.java

private final void installConfigurationValueProducerMethods(@Observes final AfterBeanDiscovery event, final BeanManager beanManager) {
  if (event != null && beanManager != null) {
  
    // Get a Configurations object.
    final Instance<Object> i = beanManager.createInstance();
    assert i != null;
    final Instance<Configurations> configurationsInstance = i.select(Configurations.class);
    assert configurationsInstance != null;
    if (configurationsInstance.isResolvable()) {
      final Configurations configurations = configurationsInstance.get();
      assert configurations != null;
      
      // Find out its set of Types.
      final Set<Type> types = configurations.getConversionTypes();
      if (types != null && !types.isEmpty()) {
      
        // Create a BeanAttributes representing our almost-producer method.
        final AnnotatedType<ConfigurationsExtension> thisType = beanManager.createAnnotatedType(ConfigurationsExtension.class);
        final AnnotatedMethod<? super ConfigurationsExtension> producerMethod = thisType.getMethods().stream()
          .filter(m -> m.getJavaMember().getName().equals("produceConfigurationValue"))
          .findFirst()
          .get();
        final BeanAttributes<?> producerAttributes = beanManager.createBeanAttributes(producerMethod);
        
        for (final Type type : types) {
          assert type != null;
          
          // For each type, create a Bean representing it.
          // The bean will be logically comprised of the BeanAttributes we made above, but
          // with its type set appropriately, and a ProducerFactory representing our
          // almost-producer method.  The combination will make this a "real" Bean
          // thus turning our almost-producer method into a "real" producer method.
          final Bean<?> bean =
            beanManager.createBean(new DelegatingBeanAttributes<Object>(producerAttributes) {
                @Override
                public final Set<Type> getTypes() {
                  final Set<Type> types = new HashSet<>();
                  types.add(Object.class);
                  types.add(type);
                  return types;
                }
              },
              ConfigurationsExtension.class,
              beanManager.getProducerFactory(producerMethod, null /* null OK; producer method is static */));
              
          // Add the Bean representing the almost-producer method to the container;
          // the almost-producer method will now handle injection points of the
          // current type!
          event.addBean(bean);
        }
      }
    }
  }
}