Java Network Programming (3rd ed) [Electronic resources] نسخه متنی

Chapter 1. Why Networked Java?

In the last 10 years, network programming has stopped
being the province of a few specialists and become a core part of
every developer''s toolbox. Today, more programs are
network aware than aren''t. Besides classic
applications like email, web browsers, and Telnet clients, most major
applications have some level of networking built in. For example:

Text editors like BBEdit save and open files directly from FTP
servers.

IDEs like Eclipse and IntelliJ IDEA communicate with CVS repositories.

Word processors like Microsoft Word open files from URLs.

Antivirus programs like Norton AntiVirus check for new virus
definitions by connecting to the vendor''s web site
every time the computer is started.

Music players like Winamp and iTunes upload CD track lengths to CDDB
and download the corresponding track titles.

Gamers playing Quake gleefully frag each other in real time.

Supermarket cash registers running IBM SurePOS ACE communicate with
their store''s server in real time with each
transaction. The server uploads its daily receipts to the
chain''s central computers each night.

Schedule applications like Microsoft Outlook automatically
synchronize calendars with other employees in the company.

In the future, the advent of web services and the semantic web is
going to entwine the network ever more deeply in all kinds of
applications. All of this will take place over the Internet and all
of it can be written in Java.

Java was the first
programming language designed from the ground up with networking in
mind. Java was originally designed for proprietary cable television
networks rather than the Internet, but it''s always
had the network foremost in mind. One of the first two real Java
applications was a web browser. As the global Internet continues to
grow, Java is uniquely suited to build the next generation of network
applications. Java provides solutions to a number of
problemsplatform independence and security being the most
importantthat are crucial to Internet applications, yet
difficult to address in other languages.

One of the biggest secrets about Java is that it makes writing
network programs easy. In fact, it is far easier to write network
programs in Java than in almost any other language. This book shows
you dozens of complete programs that take advantage of the Internet.
Some are simple textbook examples, while others are completely
functional applications. One thing you''ll notice in
the fully functional applications is just how little code is devoted
to networking. Even in network intensive programs like web servers
and clients, almost all the code handles data manipulation or the
user interface. The part of the program that deals with the network
is almost always the shortest and simplest.

In brief, it is easy for Java applications to send and receive data
across the Internet. It is also possible for applets to communicate
across the Internet, though they are limited by security
restrictions. In this chapter, you''ll learn about a
few of the network-centric applications that have been written in
Java. In later chapters, you''ll develop the tools
you need to write your own network programs.