Retrieving value from Request URL in Wicket

Question

HI,

I have a URL which will call a method my method in Java.

it looks like this

http://www.example.com/method?value=24

how can i retrieve value 24 and use it in my called method?

I am using Wicket Framework

Thanks

Answer 1

If you are using Servlets, you can use

ServletRequest.getParameter(...)

If you use JSP, you can use the request implicit object

request.getParameter(...)

Answer 2

Something like this:

public class ExampleServlet extends HttpServlet {

   /** Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
    * @param request servlet request
    * @param response servlet response
    */
   protected void service(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {

       String s = request.getParameter("value");
       int value = 0;
       try {
            value = Integer.parseInt(s);
       } catch(NumberFormatException nfe) {
            nfe.printStackTrace();
       }
   }
}

Answer 3

OK, the way to access a request parameter in wicket is this:

final Request request = RequestCycle.get().getRequest();
final String valueAsString = request.getParameter("value");
int value = Integer.parseInt(valueAsString);

But usually you don't have to do that, because you pass parameters by using BookmarkablePageLinks with PageParameters objects and read those objects from the page constructors. Read this page for some material on Bookmarkable Links in Wicket.

Answer 4

I am assuming here that you do create the number - the '24' - in your Java code, since you say you are using Wicket.

Thus, as seanizer already said, in 99% of the cases, you do not need to parse the request url to get the value, something like this should be sufficient:

public class MyPage extends WebPage {
   public MyPage() {
      // your number is generated somehow
      final int value = 24;

      this.add(new Link<Integer>("myLink") {
         @Override
         public void onClick() {
            // do something with the value
            int newValue = value * 2;
         }
      }
   }
}

or - with models - like this

public class MyPage extends WebPage {
       public MyPage() {
          // your number is generated somehow
          int value = 24;

          Model<Integer> model = new Model<Integer>(value);

          this.add(new Link<Integer>("myLink", model) {
             @Override
             public void onClick() {
                // your '24'
                Integer value = this.getModelObject();
                // do something with the value
                int newValue = value * 2;
             }
          }
       }
    }

If you really, really, REALLY-REALLY do need the parameter from the URL, I guess this is what you want:

public class MyPage extends WebPage {
       public MyPage(PageParameters parameters) {
          // your number is generated somehow
          Integer value = parameters.getAsInteger("value");
       }
    }

Depending on how you configured your application, you might need to implement the other constructors accordingly.

Good luck.