Can a JSP be multi-threaded?
Govind Seshadri By default, the service() methods of all JSP pages execute in a multithreaded fashion. Each client request is dispatched in a concurrent manner within a separate thread by the servlet engine. Thus, it is important to synchronize access to any page shared state in the default scenario.This causes the generated servlet to implement the SingleThreadModel interface.
You can make a page "thread-safe" and have it serve client requests in a single-threaded fashion by setting the page tag's isThreadSafe attribute to false:
<%@ page isThreadSafe="false" %>