Facebook application to display friend list in jsp

Question

How to create a facebook application to display friend list in jsp page without using script.

Answer 1

use FacebookConnect REST interface from jsp http://wiki.developers.facebook.com/index.php/API

Answer 2

To preprocess a request, you need to create a Servlet and implement the doGet() method. Inside this method you can freely write/invoke Java code as you want without cluttering the JSP file with scriptlets. Make use of java.net.URL and/or java.net.URLConnection inside the doGet() method to access the Facebook API by HTTP requests and obtain data as HTTP response. Finally process this data in flavor of List<Friend> and forward the request to JSP page for display.

Kickoff example:

public class FacebookServlet extends HttpServlet {
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        URL url = new URL("http://url/to/some/facebook/API/to/get/list/of/friends"); // Read Facebook API doc for the correct URL.
        InputStream input = url.openStream();
        List<Friend> friends = extractFriends(input); // Do your job here.
        request.setAttribute("friends", friends); // It's then available as ${friends} in JSP.
        request.getRequestDispatcher("/WEB-INF/friends.jsp").forward(request, response);
    }
}

Map this servlet in web.xml on an url-pattern of for example /friends so that you can invoke it by http://example.com/contextname/friends.

Then, in your /WEB-INF/friends.jsp (the JSP is placed in /WEB-INF to prevent from direct access without using the servlet), make use of JSTL (just drop jstl-1.2.jar in /WEB-INF/lib) c:forEach tag to iterate over the List<Friend> and print a HTML table row (<tr>) on every iteration:

<table>
    <c:forEach items="${friends}" var="friend">
        <tr>
            <td>${friend.name}</td>
            <td>${friend.age}</td>
            <td>${friend.email}</td>
            <td>etc..</td>
        </tr>
    </c:forEach>
</table>