Your web application requires the adding and deleting of many session attributes during a complex usecase. A bug report has come in that indicates that an important session attribute is being deleted too soonand a NullPointerException is being thrown several interactions after the fact. You have decided to create asession event listener that will log when attributes are being deleted so you can track down when theattribute is erroneously being deleted.
Which listener class will accomplish this debugging goal？（）
A.Create an HttpSessionAttributeListener class and implement the attributeDeleted method and log the attribute name using the getName method on the event object.
B.Create an HttpSessionAttributeListener class and implement the attributeRemoved method and log the attribute name using the getName method on the event object.
C.Create an SessionAttributeListener class and implement the attributeRemoved method and log the attribute name using the getAttributeName method on the event object.
D.Create an SessionAttributeListener class and implement the attributeDeleted method and log the attribute name using the getAttributeName method on the event object.
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You need to store a Java long primitive attribute， called customerOID， into the session scope.
Which two code snippets allow you to insert this value into the session？（）
A.long customerOID = 47L；session.setAttribute（"customerOID"， new Long（customerOID））；
B.long customerOID = 47L；session.setLongAttribute（"customerOID"， new Long（customerOID））；
C.long customerOID = 47L；session.setAttribute（"customerOID"， customerOID）；
D.long customerOID = 47L；session.setNumericAttribute（"customerOID"， new Long（customerOID））；
Given the definition of MyServlet：
11.public class MyServlet extends HttpServlet {
12.public void service（HttpServletRequest request，
13.HttpServletResponse response）
14.throws ServletException， IOException {
15.HttpSession session = request.getSession（）；
16.session.setAttribute（"myAttribute"，"myAttributeValue"）；
17.session.invalidate（）；
18.response.getWriter（）.println（"value=" +
19.session.getAttribute（"myAttribute"））；
20.}
21.}
What is the result when a request is sent to MyServlet？（）
A.An IllegalStateException is thrown at runtime.
B.An InvalidSessionException is thrown at runtime.
C.The string "value=null" appears in the response stream.
D.The string "value=myAttributeValue" appears in the response stream.
最新試題
Click the ’Select and Place’ button.Place the events in the order they occur.
Given a Filter class definition with this method：21.public void doFilter（ServletRequest request，22.ServletResponse response，23.FilterChain chain）24.throws ServletException， IOException {25.// insert code here26.}Which should you insert at line 25 to properly invoke the next filter in the chain， or the target servlet if thereare no more filters？（）
Click the ’Select and Place’ button.Place the events in the order they occur.
Given tutorial.jsp：2.EL Tutorial3.Example 14.5.Dear ${my：nickname（user）}6.Which， when added to the web application deployment descriptor，ensures that line 5 is included verbatimin the JSP output？（）
Which three are true about servlet filters？（）