What is a CDI bean?

Question

I am a little bit confused, we call CDI bean to the beans which we inject them using @Inject annotation or the beans which we use @Inject inside them ?

Answer 1

CDI beans are classes that CDI can instantiate, manage, and inject automatically to satisfy the dependencies of other objects. Almost any Java class can be managed and injected by CDI.

For example, PrintServlet got dependency on a Message instance and have it injected automatically by the CDI runtime.

PrintServlet.java

@WebServlet("/printservlet") public class PrintServlet extends HttpServlet {     @Inject private Message message;      @Override     public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {         response.getWriter().print(message.get());     } } 

Message.java (This class is a CDI bean)

@RequestScoped public class Message {     @Override     public String get() {         return "Hello World!";     } } 

Cheers!

Answer 2

CDI does not introduce a new bean type called a CDI Bean with its own unique component model.

CDI provides a set of services that can be consumed by managed beans and EJBs that are defined by their existing component models.

So, CDI is just a Bean (EJB or Managed Bean) handling CDI lifecycle with scope for Context and other old feature DI .