SCWCD(310-083)單項選擇題每日一練(2019.01.08)

Users of your web application have requested that they should be able to set the duration of their sessions.So for example， one user might want a webapp to stay connected for an hour rather than the webapp’sdefault of fifteen minutes； another user might want to stay connected for a whole day. Furthermore， youhave a special login servlet that performs user authentication and retrieves the User object from the database. You want to augment this code to set up the user’s specified session duration.
Which codesnippet in the login servlet will accomplish this goal？（）

After a merger with another small business， your company has inherited a legacy WAR file but the originalsource files were lost. After reading the documentation of that web application，you discover that the WARfile contains a useful tag library that you want to reuse in your own webapp packaged as a WAR file.
What do you need to do to reuse this tag library？（）

Given：
1.<% int[] nums = {42，420，4200}；
2.request.setAttribute（"foo"， nums）； %>
3.${5 + 3 lt 6}
4.${requestScope[’foo’][0] ne 10 div 0}
5. ${10 div 0}
What is the result？（）

Given this fragment in a servlet：
23.if（req.isUserInRole（"Admin"）） {
24.// do stuff
25.}
And the following fragment from the related Java EE deployment descriptor：
812.<security-role-ref>
813.<role-name>Admin</role-name>
814.<role-link>Administrator</role-link>
815.</security-role-ref>
900.<security-role>
901.<role-name>Admin</role-name>
902.<role-name>Administrator</role-name>
903.</security-role>
What is the result？（）