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Java - an update of the basics

Archive - Originally posted on "The Horse's Mouth" - 2014-11-16 16:18:08 - Graham Ellis

Java is a programming language - a way of specifying a series of operations to be performed one after another to a computer which is written in a coded way - often described as "English Like" - rather than in a binary pattern of zeros and ones which all computers work with at the lowest level.

If you're using Java, you'll usually write your operations or instructions into a file with a .java extension, and then use a program (a "java compiler") to convert those instructions into a format that's not human-readable called a "class file". That class file is designed to be efficient in operation when you run your program, to be modular so that code can easily be shared between multiple programs, and to be portable so that it can run on all sorts of different systems without needing to be changed. And in order for it to run so widely, each machine it runs on needs to be provided with a common interface to run it - that's itself a program called a Java virtual machine or JVM.



Java started off at release 1.0 and has progressed through to Java 1.8. Sun Microsystems, Java's originators, were very conservative in moving release numbers forward, sticking with "1.x" because the code written for 1.0 is still operational on 1.8 (i.e. to this day) with no breaks in compatability.

However, Java was extended and provided with so many extra packages over time that it's became a different prouct and so it was known as "Java 2" from around version 1.2 ... and that carried on until "Java 2" version 1.5. From that point onward, the marketing name has been Java 5, Java 6, Java 7 and now Java 8.

Now an Oracle product, with Oracle having bought out Sun Microsystems in 2010, Java these days is both a server and a device programming language, with web servers supporting major applications written in Java, and phones such as the Android also having their apps written in Java. The days of it being just an embedded language within a browser are a distant memory.



At Well House Consultants, we have taught Java from the early days of the language - and you'll find many examples on our web site including stand alone ones, ones to be embedded in browsers ("applets") and also server side code in the form of Servlets and JSPs (Java Server Pages).

Java is a well designed language - however, in the earlier days it was much oversold and I found that a significant proportion of delegates learning the language were doing so to use in applications for which its wasn't / isn't suited - there are circumstances where Perl or Tcl or PHP were much better in those earlier days, and today perhaps Python, Lua, PHP or Ruby might be a good decision. And so - with many other courses to offer, and many other people teaching Java, we dropped public Java courses while continuing to offer the training on closed or private courses to companies and organisations who we felt were using Java for reasons that we could endorse - of which there are many.

Progressing, Java has branched off in many directions. Where there were just 8 standard add-on packages with Java 1.0, there are now thousands, and it's simply not possible for one small company to honestly say they know them all (or even all of the common ones!) ... and training requirements will often include not only the basics, but also some extension or other. And as we just know "of" the extensions, rather that their detail, our private Java courses these days are limited to the fundamentals of programming in the language. We are happy - very happy - to teach your group "Learning to program in Java" and indeed I have a series of such courses coming up. And we also provide one area of more extended training, which is in deploying Java applications under the Apache Tomcat server - that as a public course as well as a private course - see [here].