How to use a URL like a parameter

Question

I want a simple servlet that can be used without parameters. Something like :

http://servername:8080/do/view/username/address

and use it like a parameter :

http://servername:8080/do?action=view&login=username&page=address

Both urls will have the same behaviour. I prefer don't use any framework, only servlets and filters.

How can I obtain the url name from the servlet? What's the best solution?

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Response:

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Based on the reply made by @BalusC i have created the following servlet that do all i want:

@WebServlet("/do/*")
public class ActionTestCasesServlet extends HttpServlet {

protected void doGet(HttpServletRequest request,
        HttpServletResponse response) throws ServletException, IOException  
{
  String pathInfo = request.getPathInfo();
  String[] parts = pathInfo.substring(1).split("/");
  RequestDispatcher destination = getServletContext()
            .getRequestDispatcher("/" + parts[0] + ".jsp");
  if (parts.length > 1) {
request.setAttribute("username", parts[1]);
  }
  if (parts.length > 2) {
    request.setAttribute("page", parts[2]);
  }
  destination.forward(request, response);

 }
}

This code call the "view.jsp" passing the attributes "username" and "page".

Answer 1

Just map the servlet on /do/* instead of /do.

@WebServlet("/do/*")

This way you can obtain the path information using HttpServletRequest#getPathInfo().

String pathInfo = request.getPathInfo(); // /view/username/address

You can use the usual String methods like String#split() to split it in fragments.

String[] parts = pathInfo.substring(1).split("/"); // view, username, address

See also:

• Design Patterns web based applications - for the case you intend to homegrow MVC (note: I don't recommend this, it's fun if it's for learning/hobby purposes, but if it's for real job, rather pick an existing MVC framework so that you can ensure that every pitfall is covered)

Answer 2

You say you'd prefer not to use "any framework, only servlets and filters", but have you considered the tuckey.org UrlRewriteFilter? This is a single filter that you can register in web.xml and then declare rules such as

    <rule>
        <from>/do/(.+)/(.+)/(.+)</from>
        <to>/do?action=$1&amp;login=$2&amp;page=$3</to>
    </rule>

in an XML file. Then you just write your servlets to expect the query parameters as normal and let the filter deal with the "pretty" URLs.