JAVA is a programming language that is becoming a standard for development over the Internet. This section clarifies the 'basics' on the language so that anybody who is interested in this technology can clarify some of the first questions that come into mind and, in addition, get some orientation on were to go from there.
Note: For the development you will see here I am using Microsoft's Visual J++ V6.0 (mostly because it is widely known and available) but I will try to be a generic as possible to avoid Microsoft's Windows dependency.
In its origins, the World Wide Web provided a great way to access information (just imagine, to be able to access all kind of information from anywhere around the world!) but this access was basically 'static' in nature. You could jump from one page to another but with almost no interaction. Pages and web sites were merely still images with test and, occasionally, some audio files of not so good quality.
Currently the Web is evolving to become a truly interactive world. Not only the information one can access is more attractive but also more accessible to the beginners. The interface with the user is much more friendly than years ago and this allows people to participate in this evolution.
JAVA is playing an important role in this evolution. The most important feature: Platform Independence. This means that it does not matter what machine/Operating System you use to execute your applications or applets (Windows, Mac, Unix). Your applications/applets will execute the same.
JAVA supports two different kinds of programs:
Applications are complex programs like the ones that can be created with any programming language. These are executable files that can be run by a command-line call or being double-clicked on a windowing environment.
Applets are small programs that can be run only within a Web Page (that is, they are embedded in HTML code) within a browser like Netscape, Internet Explorer, Mosaic, etc.
Some examples:
The following page shows an applet that displays the User Interface controls used in JAVA. I also provide the Source Code that you can steal, I mean, borrow and modify/play with.
https://www.angelfire.com/nc/gayosso/java/UIControlsApplet.html
Java's graphics capabilities can make applications and web sites look much more professional than just using predefined controls. An applet or application with graphics communicates better with the users than if just text is displayed.
JAVA provides many methods with which you can draw to the screen. You can create lines, rectangles, circles, etc.
The following example shows the most important graphic elements. Code is included!
https://www.angelfire.com/nc/gayosso/java/graphics/graphic.html
With JAVA you can create as many font objects as needed and select from several 'faces' available in your system (althought they are not as may as in the operating system). The color objects can also be created by using 'pre-defined values' that are browser 'safe' (meaning you can use them and be sure most browsers around the world will interpret them correctly) or by defining the three components for the RGB model (red, green, and blue).
The following applet exemplifies the use of the Graphics class to draw different font types and color. I also included code that displays the available font faces for JAVA in your system.
https://www.angelfire.com/nc/gayosso/java/fonts/fonts.html
Images is one of the features that make JAVA extremely atractive. Loading pictures into applets or applications make the programs communicate more effectively and become more powerful. They also provide an appealing look.
Image Processing in JAVA is a very useful technique as you get to save a lot of space on the server because you just have to load an image once and then display it as many times as you want adding all the effects needed. Otherwise you would have to process the image as required (with additional software) and then upload to the server all the different files needed.
The following page shows how to load images and some useful processing techniques
https://www.angelfire.com/nc/gayosso/java/images/images.html
Following are some links with very useful information (don't worry, these are free sites). Go ahead and explore, my friends.
Developed by: Lucio Gayosso. August, 2000.
Home
Background music: Yngwie Malmsteen's "Crying"
