When a request message is processed through the HttpServlet doGet
method, who sets the parameters and attributes for the
HttpServletRequest argument? And what is the difference between an
attribute and a parameter?
Client requests are passed on to a servlet through the Web server's
servlet engine. The servlet engine packages the request into a
ServletRequest object, through which request attributes and parameters
can be extracted.
The HttpServlet class examines the request and
repackages it as an HttpServletRequest before dispatching it to one of
its "do" methods, such as doGet. Attributes provide a means for the
Web server to give a servlet extra information about a request. They
do not represent data that was sent directly from the client.
Parameters are akin to function arguments. They are name value pairs
transmitted by the client and interpreted by the servlet.
example, the values submitted through an HTML form would be passed as
parameters that could be accessed through the HttpServletRequest
argument to doGet.