Summary: Simon continues his exploration of the Java language... with sample code.

Into Java, Part II - Introduction

Welcome back to this second OS/2 e-Zine! Java column. I have spent some extremely busy weeks studying computer algorithms, data structures and the complexity of algorithms. Quite a few lab works were done in Java, and it turned out that Java was almost as fast as C, depending on how the code was implemented. But now, together we will explore the always useful questions

Last time we briefly touched the history book, but today we will open the computer theory book. We all know how to make ourselves fried eggs and bacon, don't we? Then we never think about how and why we do certain things. With Java we will try to get the same deep-rooted, basic knowledge. Later we will be able to do the French cuisine. Or whatever happens to be your taste.

Because this got to be a looooooong column, I choose to divide it into three parts: a theory part, a documents part and a lab work part. The theory and lab work chapters will slightly overlap each other, that way it's possible to work through them at different times and you won't need to swap between them too much.

The theory lesson of today will concentrate on the basic structure of Java, which in fact is identical to the back bone of object oriented developing. What are the bricks to build with, the small ones and the bigger ones? Taste these words: class, method, instance, data field and constructor. Soon you will be familiar with them.

Further, as developers we'll have to dig into our on-line Java manual from time to time. After installing Java 1.1.7 with the Developer Toolkit, as we did last time we met, we now do have a rather big Java on-line manual on our hard disks. The computed size is

[C:\java11]treesize docs
"C:\java11\docs\" and subtree contains:
7.376.136 bytes in 591 files and 3 dirs 7.528.448 bytes allocated

Yes, more than 7 megabyte (size is depending on language of course), cram-full of Java-information for developers. We will find out how to use this huge collection of information, and why it's good to use it.

After so much reading, would you like to do some more coding? Hopefully you don't expect me to give you a 300 line example, or a full blown graphical applet to use. Nevertheless, we'll learn how to do the basic coding, the how's and why's I initially promised you. Practically every problem that will arise later on, can be solved faster with only a few basic steps.