Question 19 of HFSJ Final mocktest

[geeta vemula]

A Classic tag handler exists in legacy code. The author wrote a handler that evaluates its tag body a hundred times, to be used in testing other tags that produce random content.

Given:
06. public class HundredTimesTag extends TagSupport {
07. private int iterationCount;
08. public int doTag() throws JspException {
09. iterationCount = 0;
10. return EVAL_BODY_INCLUDE;
11. }
12.
13. public int doAfterBody() throws JspException {
14. if(iterationCount < 100){
15. iterationCount++;
16. return EVAL_BODY_AGAIN;
17. }else{
18. return SKIP_BODY;
19. }
20. }
21. }

What is incorrect about the code?
A. Tag handlers are not thread safe, so the iterationCount can become out of sync if multiple users are reaching the page at the same time.
B. The doAfterBody method is never being called because it is not part of the tag handler lifecycle. The developer should have extended the IterationTagSupport class to include this method in the lifecycle.
C. The doTag method should be doStartTag. As written, the default doStartTag of TagSupport is called which simply returns SKIP_BODY, causing doAfterBody to never be called.
D. When doAfterBody returns EVAL_BODY_AGAIN the doTag method is called again. The doTag method resets iterationCount to 0, resulting in an infinite loop and a java.lang.OutOfMemoryError is thrown.


Answer is C.

here we need to choose correct one or incorrect one??

[Sebastian Janisch]

There is something wrong with this question.

TagSupport does not have a 'doTag' method, only SimpleTagSupport has. There should be a doStartTag method involved.