In some instances the type of the bean we wish to inject into our code may be an interface or a Java superclass, but we may be interested in injecting a subclass or a class implementing the interface. For cases like this, CDI provides qualifiers we can use to indicate the specific type we wish to inject into our code.
A CDI qualifier is an annotation that must be decorated with the
@Qualifier annotation. This annotation can then be used to decorate the specific subclass or interface. In this section, we will develop a
Premium qualifier for our customer bean, premium customers could get perks, such as discounts, not available to regular customers.
Creating a CDI qualifiers with NetBeans is very easy, all we need to do is go to File | ...