Java Enterprise and Web Technologies

To receive the HttpServletRequest instance in a Struts 2 Action class, you implement the ServletRequestAware interface. This interface's setServletRequest(HttpServletRequest) method is called by Struts 2 before the action executes, injecting the request object. ServletResponseAware is for responses, ActionSupport is a convenience base class.

Action classes in Struts 2 are instantiated on a per-request basis by default. Each request creates a new instance of the action class, which makes actions thread-safe and stateless. This is a key difference from some frameworks where actions might be singletons. The Struts 2 interceptor stack and valueStack work with this per-request instance model.

JSF includes standard message bundles with predefined error messages for conversion and validation failures. These messages are automatically associated with components and displayed using or tags when errors occur during the Process Validations or Update Model Values phases.

BC4J (Business Components for Java) is Oracle's framework for building J2EE business applications. It provides a layer of abstraction over database operations and follows the MVC pattern. Option C correctly identifies this expansion.

JSP implicit objects are: request, response, pageContext, session, application, out, config, page, exception. 'context' is NOT an implicit object - the correct name is 'application' for the ServletContext reference.

JSP implicit objects are automatically available in JSP pages without declaration. The standard implicit objects are: request, response, pageContext, session, application (not 'context'), out, config, page, and exception (only in error pages). 'context' is not a valid implicit object name - the correct names are 'application' for servlet context and 'pageContext' for page context.

GenericServlet is a protocol-independent servlet class. It defines a lifecycle method service() called for all client requests. Unlike HttpServlet, it does not implement HTTP-specific behavior directly. The marked options correctly describe its protocol-neutral design and request handling workflow.

JSP technology provides all four listed advantages: separation of dynamic/static content through its template mechanism, support for scripting and custom tag libraries, component/tag reuse through JavaBeans and custom tags, and serving as the presentation layer in N-tier enterprise architecture.

All four statements correctly describe application scope in JSP. Objects with application scope are accessible across the entire application (all requests/sessions), persist until the ServletContext is destroyed/reclaimed, can be accessed from non-session-aware pages, and are stored in the implicit application object.

The Cookie class in Java servlets/JSP uses setMaxAge(int seconds) to set the cookie's maximum age in seconds. The parameter must be an integer, not a float. Negative values delete the cookie, zero deletes it immediately, and positive values set the expiration time.

In JSP, only jspInit() and jspDestroy() can be overridden by developers. The _jspService() method is generated by the container and cannot be overridden (it's marked final in the generated servlet). getParameter() is a method of ServletRequest interface, not a JSP lifecycle method.

Applets can communicate with servlets using HTTP requests (sending text or serialized objects), direct TCP/IP sockets, or Remote Method Invocation (RMI). Since all three communication mechanisms are valid, marking them all as correct in this multiple-response question is accurate.

While JSP pages primarily use the JspWriter implicit object 'out', developers can explicitly access ServletOutputStream through response.getOutputStream() when binary output is needed. This is valid JSP/servlet API behavior, making the statement true.

JSP and Servlets can invoke external applications using Runtime.getRuntime().exec() or ProcessBuilder. The external process runs on the server side, not the client browser. This is useful for server-side processing but requires proper security considerations.