Jakarta EE Servers and Containers

A Jakarta EE server is a server application that implements the Jakarta EE platform APIs and provides standard Jakarta EE services. Jakarta EE servers are sometimes called application servers, because they allow you to serve application data to clients, much as web servers serve web pages to web browsers.

Jakarta EE servers host several application component types that correspond to the tiers in a multitiered application. The Jakarta EE server provides services to these components in the form of a container.

Jakarta EE containers are the interface between the component and the lower-level functionality provided by the platform to support that component. The functionality of the container is defined by the platform and is different for each component type. Nonetheless, the server allows the different component types to work together to provide functionality in an enterprise application.

The Web Container

The web container is the interface between web components and the web server. A web component can be a servlet or a JavaServer Faces Facelets page. The container manages the component’s life cycle, dispatches requests to application components, and provides interfaces to context data, such as information about the current request.

The EJB Container

The EJB container is the interface between enterprise beans, which provide the business logic in a Jakarta EE application, and the Jakarta EE server. The EJB container runs on the Jakarta EE server and manages the execution of an application’s enterprise beans.

The Application Client Container

The application client container is the interface between Jakarta EE application clients (special Java SE applications that use Jakarta EE server components) and the Jakarta EE server. The application client container runs on the client machine and is the gateway between the client application and the Jakarta EE server components that the client uses.