What is the use of jsp when compare with Struts

Question

what is the use of jsp when compare with Struts

Answer 1

JSP Tag Libraries are great for reusable content formatting and ligic.
For example, let's say you have this Shopping site. Each item you sell is stored in a database, and you get them out depending on Catagories, creating a List of ItemBeans. You allways want to display the items with a catagory header, then a <table> with the item number, the description and the price.
Instead of creating a bunch of logic in the JSP that does this, you can pass it on to a Tag that might look like this in your JSP:
<shopping:itemTable catagory="${selectedCatagory}" items="${itemsForCatagory}" />
This would make the JSP easier to read and work with.
The actual uses are incredible. Have you used the <jsp:useBean ...> tag? That is an example of a use of the Custom Tag Libraries.
Furthermore, look into JSTL (JSP Standard Tag Libraries). They are a collection of tags (API by Sun, coding by Apache) used to do many of the standard actions you might want/need to do in JSPs, like a conditional tag (c:if only do something if the test is true), multiple-conditional tags (c:choos c:when c:otherwise) like an if [else if] else construct. Looping through an array or Collection (c:forEach), storeing values in scopes (c:set) formating numbers and dates (the fmt library), xml transformations (xml library), and lots of other things that you could replace scriptlet code with.