I nternet technologies
The technology that has probably shaped Java programming more than any
other is the Internet. This huge, loose collection of disparate systems is con-
nected by broadly adopted open standards. These standards form a large part of
the foundation for Java servlets that are used heavily in this topic. The Internet
standards technologies are far from spectacular. Faster, more flexible, and more
reliable communication protocols than TCP exist. The power of markup lan-
guages like Standard Generalized Markup Language ( SGML ) dwarfs the stan-
dard Internet markup language, HTML . HTTP is simple and unsophisticated.
The Internet works because the open standards are simple, widely adopted with
just enough flexibility and power to allow meaningful development.
To find out more about a standard, the ultimate source is the RFC . The
standards board that has oversight responsibilities for the engineering of the
Internet is the Internet Engineering Task Force ( IETF ). A party submits a
standard on a form called a request for comments ( RFC ). When an RFC is
adopted, it becomes the standard. The process works like this:
The IETF forms a committee that drafts a document (the RFC ).
Interested parties review the RFC and make comments.
If the reviews warrant change, the comments are incorporated into the
When debate is closed, the final version of the RFC becomes the stan-
dard and no further comments or changes are permitted.
From that point forward, changes occur through subsequent RFC s,
which can enhance, clarify, or even supersede previous RFC s.
Unlike proprietary standards, RFC s for all Internet standards are at our finger-
can be debated in a formal and open forum. If our understanding is ever
muddy or unclear, we should go right to the source of the standard: the RFC .
Internet topologies affect our applications
Let's examine the composition of the Internet with an eye toward the places
that antipatterns may develop. The nodes of the Internet interoperate through
a defined set of standard networking protocols. Since most organizations and
corporations have security concerns, attaching all computers directly to the
Internet is not practical. Instead, several layers are used for protection, as
shown in figure 2.2.