Re: jdbc, applet -> servlet;corba ??

On Sun, 4 Jun 2000, moenk S wrote:

> Hi all,.....
> 
> I'm in RedHat 6.0, Postgresql 7 and Java 1.2. I want to make
> client-server communication, to access the data.
> 
> Following the java jdbc turotial, I can access the data from applet by
> appletviewer. But when I try to running applet from browser, there
> wass an error : No Driver Suitable.  Give me suggestions please.

How are you defining the applet in the web page? You may need to merge
your applet's classes and the contents of the postgresql.jar file into a
single .jar file, and refer to it on your web page.

> Also I have question, what the different between servlet and corba ?

Servlet's are small applications written in Java, which run on the server
side of an application (not just the web).

Corba is a standard way of writing an object that can be accessible from
any platform (which has an Orb). Java2 has a simple orb, so you can have
both sides of a Corba connection running it. Check the example under
src/interfaces/jdbc/example/corba in the source.

> And which one better between the combinations like follow :
>
> DB server -> JDBC -> Applet -> Servlet 
> or
> DB Server -> JDBC -> Apllet -> CORBA  ...??

No, Applet's are the top level, visible to the user in a browser.

I'd say:

DB Server -> JDBC -> Servlet -> Applet

or

DB Server -> JDBC -> Applet

The first is better, because the JDBC code is kept on the server. Only the
applet is downloaded to the browser. The second is more common, but every
use of the applet means that the jdbc driver is also downloaded, which on
average is many time larger than the applet it'self.

You could place the following between the above two:

DB Server -> JDBC -> Servlet -- Corba --> Applet

But corba is only part of Java2, and not all browsers support it yet.

Peter

--      Peter T Mount peter@retep.org.uk     Main Homepage: http://www.retep.org.uk
PostgreSQL JDBC Faq: http://www.retep.org.uk/postgresJava PDF Generator: http://www.retep.org.uk/pdf