I have a web application running on Tomcat.
There are several calculations that need to be done on multiple places in the web application. Can I make those calculations
For the first part: Yes, these calls are independent and run in parallel when called by different threads.
For the last part: Use synchronize blocks on the concurrent object, a dummy object or class object. Be aware of cascaded synchronize blocks. They can lead into dead locks when acquired in different order.