we have the concept of jsp's and servlets right we can develop the web-pages each and everything then why what for struts inturdouced
Advantages of struts
Struts is a framework follows MVC desigen pattran. so it offers different advantages for the programmer.
It reduces the development maintance time.
Centralizetion of Configuration : Rather than hard coding information into java programs,many Struts values are represented in XML or property files. Strutsconfig.xml file is the place from where you can get all informations about your web application. It is organized, your Action class , Form bean and JSP page information is in Strutsconfig.xml so don't need to search .
Form Beans : Don't need to set the form vales to your value object . When you want to capture data from a form ( In the servlet you do request.getParameter()). In the struts you don't need to do explicitly request.getParameter(). Struts request processor will do for you. All the input data will be set to form bean.
Bean Tags : Struts provides a set of custom JSP tags (bean:write,in particular) that let you easily output the properties of JavaBeans components. Basically,these are concise and powerful variations of the standard jsp:useBean and jsp:getProperty tags.
HTML tags : Struts provides a set of custom JSP tags to create HTML forms that are associated with JavaBeans components.
Learn struts, you can learn struts through the link