Question

Below is how I retrieve the Request Parameter Map in JSF

FacesContext context = FacesContext.getCurrentInstance();
Map<String, String> requestMap = context.getExternalContext().getRequestParameterMap();

However requestMap is immutable so I can’t edit it. Is there a way to add more parameters to Request Parameter Map? Is it possible at all?

Answer 1

You would generally only do this if there was some code over which you had no control that needed such parameters. If you need to pass around request-scoped variables you should use the request map.

Java EE developers generally provide additional parameters via filters. In a servlet environment, a Filter can be used to provide parameters via a wrapper. Portlet 2.0 containers provide a similar filter API.

I you want to provide custom parameter maps in a container-agnostic manner, this can be done by via a custom ExternalContext. Configure a custom FacesContextFactory to override the default behaviour.

See the relevant specifications for details:

• Servlet 3.0 spec
• Portlet 2.0 spec
• JavaServer Faces 2.0 spec

Being more specific about why and where you want to do this in a new question might provide more useful answers.