Java Reference
In-Depth Information
In late 1998, my Java proof-of-concept team designed an application that
was to be deployed in a Canadian government organization and used by
Canadian citizens. We treated round-trip communications like gold because
the quality of the Canadian phone system is not uniformly as strong as the
U.S. counterparts. In some cases, we could not even expect a 14.4 connec-
tion. Our deployment succeeded, where our competition failed, with fewer
programmers, less advanced technology, and less support for the latest stan-
dards because our solution made fewer round-trip communications.
The security policy of the firewalls is out of our control
If we are building server-side code and our customer is a corporate customer,
then we must deal with one or more firewalls
on each side of the communica-
tion
. In most cases, we do not fully control the security policy of the firewalls
on both sides of the communication. Therefore, we must make sure that our
applications use only the most basic communication protocols and standards.
In early 1996, my Java proof-of-concept team was asked to build a proto-
type of a Java application for a city government to show legal cases to govern-
ment employees. We were told that the applications and users would all be
within the same firewall. Due to complex user-interface requirements, we built
a sophisticated applet with lots of bells and whistles. We connected directly to
the database with Java Database Connectivity (
JDBC
). (After all, it was only a
prototype.) Our project was a huge success.
We were later called back to the customer to fix a few bugs in our proto-
type. The customer had a consultant come in and deploy the prototype with
very few changes. The application was so successful that many outside the city
legal department wanted to see it and use it. Though we had recommended
against deploying this application in its prototype state for this reason, we
wound up fixing it because an executive played a round of golf with our cus-
tomer. My team never again assumed that we controlled the deployment
topology or security policy of a firewall. Let's explore the open standards that
are fair game for our deployments.
2.2.3
Standards enable the Internet and add layers
If hardware has powered the Internet, software has united it. Though there
are tens of thousands of disparate hardware platforms doing the grunt work,
standards have allowed them to work together with remarkable cohesion. Post
Office Protocol (
POP3
) and
SMTP
are standards for email. Emerging stan-
dards like Wireless Markup Language (
WML)
serve pervasive computing. Sev-
eral standards are particularly important to us; for example,
TCP
and
IP
are
