struts work flow begins from jsp pages(when user first hit 
on the submit button),then UR request go and refer in 
struts-config.xml to confirm whether the corresponding  
action class entry has been put and also refer whether the 
corresponding Bean class entry has been put or not,
If the entry Has been identified then that Bean class 
should be populated and then corresponding action class 
also be populated finally ActionForward  instance goes to 
struts-config.xml(GLOBAL-FORWARD).This cyclic process taken 
place for all the request.