Sets the header specified by the name property to the value
specified by the value property.
if (value.length() == 0 || name.length() == 0) {
throw new JspTagException("setHeader: " +
"one of the attributes is not set");
}
PageContext pageContext = (PageContext) getJspContext();
HttpServletResponse response =
(HttpServletResponse) pageContext.getResponse();
response.setHeader(name, value);