Question

I have a controller with two render methods that take different arguments:

class MyController
{
  @RenderMapping
  public void render(@ModelAttribute ClassX param)
  {
    // do some stuff
  }
  @RenderMapping
  public void render2(@ModelAttribute ClassY param)
  {
    // do different stuff
  }
}

Of course what is missing in the example above is some specification for spring to know which of the render methods to invoke. I need to decide this based on a state stored in the current session. I can’t specify this just as a simple annotation, can I?

An alternative idea is something like this:

class MyController2
{
  @RenderMapping
  public void render(RenderRequest request)
  {
    if (request.getPortletSession().getAttribute(...) ...)
    {
      ClassX param = retrieveObjectFromRequest(ClassX.class, request);
      // do some stuff
    }
    else
    {
      ClassY param = retrieveObjectFromRequest(ClassY.class, request);
      // do different stuff
    }
  }
}

But in this case… How do I implement the retrieveObjectFromRequest method?

Answer 1

OK, after scrolling Spring’s source code for a while I figured a way to do the retrieveObjectFromRequest part:

class MyController
{
  @RenderMapping
  public void render(WebRequest webRequest)
  {
    ClassX param = new ClassX();
    new WebRequestDataBinder(param).bind(webRequest); // Fills param's properties.
  }
}