Java Servlets, JSP and C Programming Quiz

The jspInit() method is the correct JSP lifecycle method for initialization. You can declare it in a declaration element <%! ... %> as shown, and the JSP container will call it when the servlet is initialized. Option B is incorrect because identifiers can start with jsp. Option C is wrong because the method name is jspInit(), not _jspInit() (which is for internal implementation details).

The code won't compile because it tries to use the implicit object 'request' inside a declaration <%! ... %>. Declaration elements are for class-level variables and methods, where request (which is method-local in _jspService()) is not accessible. Additionally, there's a variable name mismatch - class1 is declared but class is used. Option A correctly identifies this as a compilation error.

The getLastModified() method in HttpServlet returns a long value representing milliseconds since the epoch (January 1, 1970). This matches the Last-Modified HTTP header format. It does not return java.util.Date or java.sql.Date objects, nor does it return an int. Option D is correct.

Calling request.getSession(false) when no session currently exists returns null. Attempting to call .getId() on that null reference immediately triggers a NullPointerException.

PageContext.findAttribute(String name) searches for an attribute across all four scopes in order: page, request, session, and application. It returns the first match found or null if not found in any scope. Option B correctly describes this behavior. Option C is wrong because it's not limited to page scope only.

The web-resource-collection element in web.xml requires web-resource-name (to identify the collection) and url-pattern (to specify which URLs are protected). The http-method element is optional - if omitted, it applies to all HTTP methods. The auth-constraint element is separate from web-resource-collection. Options A and B are correct.

The ServletContext interface defines getResource(String path), which returns a URL object, and getResourceAsStream(String path), which returns an InputStream object.

The HttpServletRequest interface specifies getHeaderNames() which returns an Enumeration of String header names. Option A is correct. Option B is wrong because getHeaders(String) returns an Enumeration of String values (all values for a multi-value header), not a String array. Option C is incorrect because getHeaderValues is not a standard method (likely confused with getHeaders). Option D is wrong because there's no getIntParameter method (use getParameter() then parseInt).

PageContext.include(String relativeUrlPath) includes the specified resource and executes it. Option C correctly identifies this signature with a single String parameter. Option D is also correct because this method is available for use within Tag handler classes. Option B is wrong - there's no two-parameter version with just request and response. The method exists (unlike option A claims).

In JSP custom tags with body content, the JSP container manages out/out nesting using pushBody() and popBody(). pushBody() is called after doStartTag() and before doInitBody/doAfterBody to save the current out. popBody() is called after doAfterBody() and before doEndTag to restore the previous out. Options A and C correctly describe this lifecycle. The timing in options B and D is incorrect.

In JSP custom tags, the getParent() method of a Tag handler returns its parent tag. For top-level tags, it returns null, and for nested tags, it returns the innermost enclosing tag handler instance.

To maintain a session during a client-side redirect, you must encode the redirect URL using HttpServletResponse.encodeRedirectURL(String url), which appends the session ID if cookies are disabled. encodeURL is used for normal links.

The auth-constraint element in web.xml specifies which roles are authorized to access protected resources. It contains role-name elements (plus optional description). Option A is correct. Option B is wrong because auth-constraint uses actual role names, not just those in security-role-ref. Option C is incorrect because auth-constraint is a subelement of security-constraint, not web-resource-collection. Option D is misleading - it's about authorization (who can access), not authentication (verifying identity).

A Java class can be compiled successfully without a main method. The main method is only required if you want to run the class as an application. Classes without main methods can be compiled and used as libraries, or they can be extended/instantiated by other classes that do have main methods. The Java compiler (javac) compiles any valid Java syntax regardless of whether a main method is present. The main method is an entry point for execution, not for compilation.

In the expression *a + 1 - *a + 3, the pointer dereference *a cancels out with -*a, leaving 1 + 3, which evaluates to 4.

Tracing the loop: i starts at 0. The condition +(+i--)!=0 uses i before decrement (i=0, i-- makes i=-1 after, but condition uses 0). 0!=0 is false, so loop never executes. After loop, i=-1. The printf outputs -1. The claimed answer A is correct.