Java Enterprise and Web Technologies

Stateful session beans maintain conversational state with a specific client and are created when the client invokes the create() method on the Home interface. They cannot be shared between clients - each client gets its own bean instance.

Message-driven beans are different from session and entity beans - they don't have business interfaces (Remote/Local) that clients call directly. Instead, they listen to JMS messages and process them asynchronously, so they lack a Component interface.

Entity beans represent persistent data and can be shared between multiple clients accessing the same entity. They MUST have an EJBObject interface for remote access. Options A and C are both correct characteristics of entity beans.

SmartClient is an enterprise-grade web application platform that provides a zero-install Ajax engine, rich UI components, and robust client-server databinding systems.

AJAX (Asynchronous JavaScript and XML) is designed specifically for asynchronous communication between the browser and server. This allows web pages to update partially without reloading the entire page. Synchronous communication would block the browser, and socket connections are not the primary mechanism AJAX uses.

SmartClient is a comprehensive web framework that supports multiple communication protocols, including Web Services (WSDL/SOAP), Direct Web Remoting (DWR), and custom JavaScript RPCs.

Apache Struts is a web application framework for Java that facilitates developing web pages. It uses MVC (Model-View-Controller) architecture and extends the Java Servlet API. While it relates to web architecture, it's not specifically an EJB alternative (though it can work alongside or replace some EJB use cases) nor is it just a design pattern.

Apache Struts is an open-source web application framework hosted by the Apache Software Foundation. It follows the Model-View-Controller (MVC) pattern and is used for developing Java web applications.

BBE (Broadband Engine) messaging architectures utilize both JMS (Java Message Service) for asynchronous messaging and SOAP (Simple Object Access Protocol) for synchronous web services.

JMS stands for Java Message Service, which is a Java API that allows applications to create, send, receive, and read messages in enterprise messaging systems.

BBE uses both JMS (Java Message Service) and SOAP (Simple Object Access Protocol) for messaging. These are two different messaging patterns used in enterprise integration.

JMS stands for Java Message Service. It's a Java API for messaging systems that allows applications to create, send, receive, and read messages.

SOAP (Simple Object Access Protocol) is a messaging protocol for exchanging structured information in web services using XML. It provides a framework for web services communication independent of platform and implementation.

Presentation server (SAPgui) runs on user workstations and provides the graphical interface. Application server executes ABAP programs and manages data flow between presentation and database layers.

UDDI (Universal Description, Discovery, and Integration) is the protocol used for web service directories/registries. It provides a standard way for businesses to publish and discover web services. WSDL describes individual services, not the directory protocol itself.