Question - What do you mean by Servlet Reloading?
Answer -
Servlet reloading may appear to be a simple feature, but it’s actually quite a trick—and requires quite a hack. The objects in ClassLoader are developed to load a class just once. To solve this limitation and to load servlets multiple times, servers use custom class loaders. These custom class loaders load servlets from the default servlets directory.
When a server dispatches a request to a servlet, it first checks if the servlet’s class file has changed on disk. If the change appears, then the server abandons the class that the loader used to load the old version and then creates a new instance of the custom class loader to load the new version. Old servlet versions can stay in memory indefinitely, but the old versions are not used to handle any more requests.