Threading security issues for Servlets and STRUTS2

Typically, after a single instance of the servlet is generated, a new thread is requested for each user . If many requests come at the same time, multiple threads may concurrently access the same Servlet object. The servlet is thread insecure and there are some limitations when multithreaded access to the servlet:

• Try not to have member variables;
• If there is a member variable, this member variable is also a stateless member variable;
• If you want to have a member variable, this member variable can only be read-only ;

STRUTS2 itself is a multi-instance, single-threaded, so it can be said that itself is thread-safe.

(The action is thread-safe because the action is in multiple cases in struts2)

Threading security issues for Servlets and STRUTS2