After reading this chapter, you should:
know one multi-purpose method for transferring image, sound and video fi les
across a network;
know a second method for transferring image fi les only across a network;
know two methods for displaying images in Java;
know how to use Java for playing sound fi les;
be aware of the API that needs to be downloaded for the playing of video fi les;
know how to use the Java Media Framework for playing audio and video fi les.
In the early days of the Internet, the only type of data that could be transferred was
text. Gradually, fi le formats that allowed the transfer of data associated with other
media came onto the scene. Notable amongst these formats was GIF ( Graphics
Interchange Format ), the most enduring graphics fi le format, which fi rst appeared
in 1987. However, it took the emergence of HTML and the World Wide Web in 1991
to awaken users to the full potential of the Internet as a vehicle for communication.
As this potential dawned upon users, they began to crave more fl exible, more varied
and more complete ways of conveying and accessing information—which meant
the transfer of data in all its media (textual, graphical, audio and video). The use of
such multimedia data has since mushroomed, in spite of the technical problems
related to fi le size and speed of transfer. These problems still exist, of course, but
have been considerably alleviated by the greater bandwidth provided by many of
today's networks and will undoubtedly continue to diminish over the coming years,
as the technology advances.
One means of supplying multimedia information and entertainment over the
Internet is provided by Java applets (which will be covered in the next chapter).
Applets have been an integral part of Java since its earliest days and played a great
part in the initial popularising of the language, though their use has waned consider-
ably in recent years with the increasing popularity of scripting languages such as