Question

Why do we need to restart a tomcat server whenever a class file is changed, is there no other way?

Answer 1

You can configure Tomcat and make your webapp “reloadable”. To do so, add reloadable=true to the <Context> element of your webapp. About the reloadable attribute, the documentation says:

Set to true if you want Catalina to monitor classes in /WEB-INF/classes/ and /WEB-INF/lib for changes, and automatically reload the web application if a change is detected. This feature is very useful during application development, but it requires significant runtime overhead and is not recommended for use on deployed production applications. That’s why the default setting for this attribute is false. You can use the Manager web application, however, to trigger reloads of deployed applications on demand.