Conflict between @FormParam and ${param}

Question

I can use Expression Language to print a POST form value from current request in my view:

<p>Foo Name: ${fn:escapeXml(param.fooName)}</p>

But param.fooName EL variable is no longer populated when I capture form data into a Java variable using the @FormParam annotation in my controller:

@FormParam("fooName") String fooName

Full flow goes like this:

1. Browser submits form to http://localhost:7101/myapp/rs/foo/new:

   @POST
   @Path("/new")
   @Consumes(MediaType.APPLICATION_FORM_URLENCODED)
   @Produces(MediaType.TEXT_HTML)
   public Response saveNew(
       @FormParam("fooName") String fooName // <---
   ) {
       Map<String, Object> map = new HashMap<String, Object>();
       // Do stuff here
       return Response.ok(new Viewable("/foo/new", map)).build();
   }
   

2. View is rendered from new.jsp:

   <%@ page contentType="text/html" pageEncoding="UTF-8" %>
   <%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>
   <p>Foo Name: ${fn:escapeXml(param.fooName)}</p>
   

If I remove the @FormParam("fooName") String fooName line then ${fn:escapeXml(param.fooName)} contains form data again.

Is there a way to access form data in both locations (Java controller and JSP view)?

Answer 1

Bug or feature, @FormParam seems to have side effects. However, form data is available at javax.servlet.http.HttpServletRequest so:

@POST
@Path("/new")
@Consumes(MediaType.APPLICATION_FORM_URLENCODED)
@Produces(MediaType.TEXT_HTML)
public Response saveNew() {
    // null when it doesn't exist (no exception thrown)
    String fooName = request.getParameter("fooName");

    Map<String, Object> map = new HashMap<String, Object>();
    // Do stuff here
    return Response.ok(new Viewable("/foo/new", map)).build();
}

<%@ page contentType="text/html" pageEncoding="UTF-8" %>
<%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>
<p>Foo Name: ${fn:escapeXml(param.fooName)}</p>