J2EE Web Technologies - JSP, Servlets and JDBC

The executeUpdate() method returns an integer representing the number of rows affected by INSERT, UPDATE, or DELETE operations. This allows applications to verify whether the operation succeeded. Option A is imprecise (doesn't specify what's returned), and option C is incorrect; there's only one executeUpdate method signature that returns int.

Transactions require auto-commit to be disabled BEFORE starting transactional operations. This allows multiple statements to be grouped together and either committed (all succeed) or rolled back (all fail) as a unit. Option C is false because auto-commit must be turned off before, not after, the transaction begins.

Varargs (...) must be the last parameter in a method signature. Option A places varargs last, so doCalc(1,2) maps x=1, args=[2], and doCalc(2) maps x=2, args=[]. Option B fails because varargs cannot precede a required parameter. Option C won't compile for the given calls, and option D has incorrect syntax.

Local variables in Java must be initialized before use. The doPlay() method declares int x but doesn't initialize it before using ++x. This is a compile-time error, unlike instance variables which receive default values. The ++x operator attempts to read x's current value before incrementing, but x has no value.

JSP's primary advantage over Servlets is allowing Java code to be embedded directly in HTML using scriptlets and expressions. In Servlets, HTML must be embedded within Java strings using out.println(), making HTML-heavy pages cumbersome. JSP reverses this; HTML is the primary content with Java interspersed where needed.

JSP pages are translated into Servlets, and the lifecycle methods reflect this. jspInit() is called once when the JSP is first loaded (like init()). _jspService() handles each request (like service()). jspDestroy() is called when the JSP is unloaded (like destroy()). Options in B are Servlet lifecycle methods, not JSP-specific.

In MVC architecture, JSP serves as the View layer, responsible for presenting data to users. JSP's strength is templating and rendering HTML with dynamic content. Servlets typically act as Controllers (handling request processing), and JavaBeans/POJOs serve as Models (data and business logic).

JSP translation is the process where the web container converts JSP pages into Java Servlet source code. This happens automatically - the first time a JSP is accessed, it's translated to a Servlet, compiled to bytecode, and then executed. Subsequent requests use the compiled Servlet directly. Options A and B describe parsing or static content generation, not the translation process.

J2EE architecture supports multiple client types. Applets can be J2EE clients (RMI/IIOP), Web Browsers access via HTTP/HTTPS, and Wireless clients (WAP, mobile) access through specialized servlets/JSP. All three are valid J2EE client types, making 'All the above' the correct answer.

JSP allows embedding pure Java code through scriptlets (<% ... %>). You can write any valid Java code inside these scriptlet blocks. However, this is considered poor practice in modern JSP development - JSTL tags, EL expressions, and MVC patterns are preferred. The question asks about capability, not best practices.

In J2EE web applications, all custom servlets handling HTTP requests must extend javax.servlet.http.HttpServlet. This abstract class provides HTTP-specific functionality (doGet, doPost, etc.). While you could technically implement Servlet directly, HttpServlet is the standard base for all HTTP servlets in J2EE.

JSP translation to Servlet happens ONLY ONCE - when the JSP is first accessed. The container generates the Servlet code, compiles it, and loads it. All subsequent requests reuse the same compiled Servlet instance. Translating on every request would destroy performance. This is why JSP changes require redeployment or container restart.

JSP pages can include both JSP pages AND HTML pages using directives like jsp:include or <%@ include %>. The statement claims inclusion is restricted to JSP only, which is incorrect. Therefore the answer is False.

You CAN write a constructor for a Servlet, but the servlet container (not your code) calls the no-argument constructor during instantiation via reflection. If you write a parameterized constructor, it won't be used. The option 'Yes, but always call the default constructor' is misleading - the container calls it, not your code. Option A is technically correct but poorly phrased.

JSP provides four scope options for storing and sharing data: page (default, most limited), request, session, and application (broadest). Page scope only lasts for the current page, request scope lasts for one HTTP request, session scope persists across multiple requests from the same user, and application scope is shared across all users and sessions.

ServletContext provides information about the servlet container and allows servlets to communicate with it. It gives access to container-wide configuration parameters, resources, and attributes shared across all servlets in the application. It does not provide information about individual requests or sessions - those are handled by HttpServletRequest and HttpSession respectively.

JSP provides several implicit objects automatically available without declaration: request (HttpServletRequest), response (HttpServletResponse), session (HttpSession), and application (ServletContext). These objects handle client requests, server responses, user session management, and application-wide operations respectively. Option C correctly lists four key implicit objects.

POST is more secure than GET because POST data is sent in the HTTP request body, not visible in the URL. GET appends form data to the URL, making it visible in browser history and server logs, and has length limitations (typically 2048 characters). POST can send much larger data and is the standard method for sensitive information like passwords. Option A incorrectly reverses the length limitations, and Option C is false.

When a JSP page is first requested, the web container translates it into a servlet class and creates a servlet instance. This instance then handles all subsequent requests to that JSP. The servlet lifecycle (init, service, destroy) applies to the generated servlet, not directly to the JSP source code. Therefore, a servlet object is indeed created during JSP execution.

The web.xml file is the standard deployment descriptor for Java web applications. It contains configuration information for servlets, filters, listeners, welcome files, and other web application components. The web container reads web.xml during deployment to understand how to initialize and run the application. Option A (ejb-jar.xml) is for EJB modules, and the file must be specifically named web.xml.