Question

I want to create a JSP page or servlet that will work in 2 ways.

A user visits their own profile page:

http//something.com/profile/

Or they visit their friends page:

http://something.com/profile/FriendsName

They could also visit their own page through an explicit URL like:
http://something.com/profile/YourName

I have a servlet-mapping setup as follows to map any requests to /profile to my JSP that will handle that request.

  <servlet>
          <servlet-name>Profile</servlet-name>
          <jsp-file>/profile.jsp</jsp-file>
  </servlet>

  <servlet-mapping>
    <servlet-name>Profile</servlet-name>
    <url-pattern>/profile</url-pattern>
  </servlet-mapping>

Then I was thinking I could setup a filter that will parse the HTTPServletRequest’s URL to read after the /profile/.

  <filter>
    <filter-name>profile-filter</filter-name>
    <filter-class>ProfileFilter</filter-class>
  </filter>

  <filter-mapping>
    <filter-name>profile-filter</filter-name>
    <url-pattern>/profile*</url-pattern>
  </filter-mapping>

Now the filter could set attributes in the HttpServletRequest, how would i go about pulling those out in the JSP page to check if a user name was specified and check if your own name was set?

How would I go about creating a page scoped bean in the ServletFilter so I could use in the JSP page using jspBean like this:

<jsp:useBean id="profileInfo" scope="page" class="ProfileInfo" /> 

Answer 1

I think a filter only serves to artificially break the logic apart. You can very easily determine the value of the portion of the URL that doesn’t match the url-pattern described in the web.xml. The HttpServletRequest class has a method that returns this value for you, it’s called getPathInfo(). Here’s an example:

<%
   String path = request.getPathInfo();
   if (path == null || "".equalsIgnoreCase(path)) {
      // The path was empty, display the current user's profile
   } else {
      // Display the named profile
   }
%>

This doesn’t help you at all with the request beans, but I think it helps with the design.