I wanted to think of something better where i can define the template in exactly one file and i do not have to include that file on every new page i add. something pretty much close the RubyOnRails "<% yield %>' directive to import the page content inside the template. i finally managed to do it.
I'll use two simple pages to illustrate the concept:
mahmoud.jsp
and index.jsp
what we want is to have each of the two pages displayed in a layout where is one header, banners and so. which will look like the following.
I was able to do this using a servlet that intercepts the request. and loads the template jsp file and pass the desired page to as a parameter to be included.
The template file is called template.jsp will look like:
The only line that matters in the template code is where we make the jsp:include page="<%request.getParameter("targetPage")%>"
The servlet intercepts http requests and loads this template using RequestDispatcher and passes the original desired page as a parameter:
The Servlet and servlet mapping in web.xml will look like
A note to be mentioned is that I had to configure my template to be initiated with requests to html pages (i can choose to work on any extension except jsp). When I configure my servlet mapping to be associated with jsp URLs, i get stuck in an infinite loop as since including the page inside the template results in a new jsp request.
The idea is simple. You are free to create your own template and to work on any file extensions in the url, but you have to specify a type other than jsp to avoid the infinite loop trap.
Bon appetite
