How to use @FormParam if form elements are dynamically created

Question

Since html form elements are dynamically created in this application, the number of elements are not known. How does one obtain element information using @FormParam annotation? For example, the below code obtains information for two form elements:

    @POST
    @Path("/newpage")
    @Produces("text/html")
    public String func(@FormParam("element1") String firstElement,
                       @FormParam("element2") String secondElement) throws IOException 
    {
         // your code goes here
    }

This is not possible as we don't know the number of elements.

Answer 1

I can't think of a way to do this using @FormParam but you can use @Context to access the HttpServletRequest (which references a map of all form parameters):

// you can make this a member of the Resource class and access within the Resource methods
@Context
private HttpServletRequest request;

@POST
@Path("/newpage")
@Produces("text/html")
public String func() throws IOException 
{
    // retrieve the map of all form parameters (regardless of how many there are)
    final Map<String, String[]> params = request.getParameterMap();

    // now you can iterate over the key set and process each field as necessary
    for(String fieldName : params.keySet())
    {
        String[] fieldValues = params.get(fieldName);

        // your code goes here
    }
}

Answer 2

The correct answer is actually to use a MultivaluedMap parameter to capture the body (tested using Jersey):

@POST
@Consumes(MediaType.APPLICATION_FORM_URLENCODED)
@Produces(MediaType.TEXT_HTML)
public String post(MultivaluedMap<String, String> formParams)
{
 ... iterate over formParams at will