How to redirect user when certain condition is met using REST JAX-RS implementation?

I used to just use Tomcat and JSP pages which I can execute query, then assign query result into the array or object then pass that data onto client side via response.

request.setAttribute("errorMessage", "this is error!!");
request.getRequestDispatcher("report.jsp").forward(request, response);

In client jsp code, I could do something like:

${errorMessage}

Then the "this is error!!" message would show up.

I want to do the same thing with REST JAX-RS GlassFish v3.

    @Path("schedule/test")
    @POST
    @Consumes("application/x-www-form-urlencoded")
    @Produces("application/vnd.ms-exce开发者_运维百科l")
    public Object tmpTest(String content) {
        try {

            //just my method to execute query and get result
            Vector out = (Vector)QueryManager.executeQuery;

            //if query result is empty, I want user to redirect to report.jsp page
            if(out.isEmpty()) {
                request.setAttribute("errorMessage", "This is error!!");
                request.getRequestDispatcher("report.jsp").forward(request, response);
                return null;
            }
        ....continue code......
   }

This results in mysterious exception I've never seen.

java.lang.ClassCastException: $Proxy109 cannot be cast to org.apache.catalina.core.ApplicationHttpRequest
            at org.apache.catalina.core.ApplicationHttpRequest.getRequestFacade(ApplicationHttpRequest.java:1001)
            at org.apache.catalina.core.ApplicationDispatcher.doDispatch(ApplicationDispatcher.java:472)
            at org.apache.catalina.core.ApplicationDispatcher.dispatch(ApplicationDispatcher.java:379)
            at org.apache.catalina.core.ApplicationDispatcher.dispatch(ApplicationDispatcher.java:336)
            at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:314)

So how can I redirect a user to report.jsp and also pass message like "This is error" ?

The client jsp expects the error msg variable to have a value:

<b>${errorMessage}</b>

That's not RESTful. You need to throw a WebApplicationException with a specific status code so that the client understands what exactly went wrong. E.g. when it's actually the server's mistake:

throw new WebApplicationException(Response.Status.INTERNAL_SERVER_ERROR);

Or when it was after all client's mistake:

throw new WebApplicationException(Response.Status.BAD_REQUEST);

See also HTTP status code definitions for an overview.

The ClassCastException which you're facing is by the way occurring because the dispatched request is actually not an instance of the servletcontainer-provided implementation (in this particular case, the one of Tomcat or a Tomcat-fork). After all, you shouldn't be doing it this way. You're developing a REST webservice, not a JSP/Servlet website. It are two distinct worlds.

As mentioned before, you should try WebApplicationException.

I believe you this would give you your desired answer:
Try this:

        if(out.isEmpty()) {
             java.net.URI location = new java.net.URI("report.jsp");
             throw new WebApplicationException(Response.seeOther(location).build());
         }