Struts 1.x vs Struts 2.x Main Differences
In struts 1 front controller is ActionServlet
In 2.x front controller is FilterDispatcher
In struts 1.x we have RequestProcessor class
In 2.x we have Interceptors instead RequestProcessor will see about this concept later just remember as of now
In struts 1.x we have multiple tag libraries like, html, logic, bean..etc
In 2.x we do not have multiple libraries, instead we have single library which includes all tags
In struts 1.x the configuration fine name can be [any name].xml and we used to place in web-inf folder
In 2.x the configuration file must be struts.xml only and this must be in classes folder
In struts 1.x we have form beans and Action classes separately
In 2.x form bean, Action classes are combinedly given as Action class only, of course we can take separately if we want ;)
In struts 1.x properties file must be configured in struts-config.xml
But in 2.x we need to configure our resource bundle(s) in struts.properties file
In struts 1.x we have programmatic and declarative validations only
In 2.x we have annotations support too along with programmatic and declarative validations