Check out the Struts documentation, such a paragraph in the documentation telling when using Struts is a good choice.
If you need to write a Very Simple Application, with a Handful of Pages, The you might consider a "Model 1" Solution That Uses Only Server Pages.
Understand: If you use a simple application using application knowledge, use normal JSP.
But, if you are writing a more complicated application, with dozens of pages, that need to be maintained over time, then Struts can help. For more about whether Model 1 or or MVC / Model 2 is right for you, see Understanding JavaServer Pages Model 2 Architecture and Issues in Struts Adoption.
Understand: However, if it is a more complex application, there are many pages that need to be maintained at any time, Struts is a good choice.
