Set attribute into JSP PageContext for use in EL from a Filter

How can I put an attribute开发者_JS百科 into the JSP PageContext for the current request (so that it becomes accessible via ${myVar} ) from a Filter that runs before the JSP?

I think I may be missing something, but:

• you have the ServletRequest object in the filter
• call request.setAttribute("myVar", value);
• call chain.doFilter(request, response);