More than one Singleton in one servlet container (Tomcat)

Question

I have my own environment for creating a Java application, and within this framework, I create my own Threadpool artist service, which is singleton. Thus, every web application using my framework will create 1 Threadpool executor at startup to use it internally.

My questions:

• Suppose I deploy 2 web applications in one Tomcat, will these 2 stream pools interfere with each other?
• Is it possible when a thread from the 1st web application will access Threadpool from the second web application or vice versa?
• Do I need to create one Threadpool service for all my web applications that are in the same servlet container, instead of one for each web application?

Thanks.

Answer 1

• Not. Webapps must be isolated by ClassLoader in Tomcat, so each must have its own singleton instance.
• While the answer to # 1 is actually not, then the answer to this question is also missing.
• Probably no.

As an aside, I understand that, as a rule, Java EE web applications should not create new threads.