About Question enthuware.jwpv6.2.691 :

[ETS User]

I think it is necessary to add valid "session" parameter to explanation to make it clear that "taglib" is the correct answer.

[admin]

The explanation has been updated.
Thank you for your feedback!

[goetz]

Explanation under isThreadSafe:

The JSP standard allows multiple instances of a JSP to exist for JSPs that are not thread safe. This enables the container to handle requests more efficiently .

However, the JSP spec says regarding isThreadSafe:

Indicates the level of thread safety implemented in the page. If false then the JSP container shall dispatch multiple outstanding client requests, one at a time, in the order they were received, to the page implementation for processing.

It seems the spec is mandating the container to serialize access against a single JSP servlet instance? This goes against what the Servlet spec says regarding SingleThreadModel, which allows implementation to serialize OR create multiple instances.