A sample web.xml

Question

a sample web.xml
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd">
// bla blahi use this type of web.xml .
my problem is to see the DTD "http://java.sun.com/dtd/web-app_2_3.dtd"
why it is "http://java.sun......." ??
does it read the DTD via internet ONLINE when i run my application ?
when i put this same web application in a no-internet connected machine, the web application works.
why then it is "http://java.sun......." ?
can i download that DTD in my hard disk and put "file:///dtd_location_in_my_drive" ?

Answer 1

You are definitely a java guru . Thank you, but I am still a novice.
BTW, you have told
I never encountered the case when it is not.1) r u sure all know professional servers keeps a
copy of that DTD .
if the server is not registered and dont have a copy
, then what you would do ? Any J2EE compliant application server should have this. I am not sure if this is mentioned in the specifications, but this is the way it goes. I have seen it in Tomcat, JBoss, Sun One, Weblogic and Websphere. I think this sample is representative enough for the family of J2EE application servers.
Logically, someone must have thought of the fact that people cannot be online all the time and they need to validate their deployment descriptors. The best way to achieve this is to provide a local copy.
because in that case server is going to throw an
exception as soon as you are going to start the
e server .
How do you solve this problem I don't know, honestly. Maybe I would copy it somewhere on the local drive and write the code like the application servers do.
will you copy the DTD file from tomcat and put it in
your WEB-INF directory and metion this path in your
web.xml ? In the worst case, yes. But that's irrelevant. If something like this is happening to the application server, it is better to find a new one. :)
in any case, i am surprised to see that i am not been
able to download this DTD fle from Sun website. why?
It is alwasy better to download this stuff and keep
it in the hard disk and specify the path in the
web.xml . i hope, this will resolve all the problems
of whether the server is registered or not.As I mentioned, you need not bother about that unless you are a fervent advocate of Murphy's law.
unfortunately, i am not been able to download this
stuff from Sun !Just paste that URL in the browser when you have an internet connection, you will be able to get the DTD.