Java Programming Tutorial - Unit 0 - The Basics

Unit 0?  If you're new to this world, it might seem odd, but you'll see why we start 0.  If not, well you probably might skip this post for now.

If you decided to stay and read on, then welcome to the world of computer programing, where media reports are exaggerated and computers are very dumb ;)

A brief intro to programming

Cheesy Java code

Programming is "the act of instructing computers to perform tasks".  Computers don't get it when you tell them "write text".  What they do understand however is a series of bits, which ultimately lead to the text being written.

I'm not going into the great detail about the origins of programming, however the following is a very brief overview to put you in context.

The first computer programs consisted primarily of punch-card.  These were the earliest forms of bits, holes to represent 'on' or '1' and solid wood for 'off' or '0'.  As time went by, digital valves were used and nowadays we use semiconductors and integrated chips.  The concept has remained the same though.  Writing ones and zeros is of course complex, so much so that no one has ever actually programmed in ones and zeros.  What they did do was devise a system to write meaningful text and then convert it to ones and zeros.  For example, the earliest code, in Assembly Language, would have looked like this

It is complicated, unless you're an engineer in the 50's (although it's fair to note that it is still used today for very specific reasons).  The development of programming languages was just like this exact case.  A language becomes too unwieldy (projects gets larger and reaches the practical limitations of the language), so a new higher level language is created to cater for new features.

The next language then uses a single command to represent a group of lower level commands.  As you might expect, it is vastly more complex than just wrapping the lower level, but you get the idea.  A tool that converts the high level language to the lower level is called a compiler.

Once computers became mainstream, more and more different kinds of architectures were created.  An architecture is a CPU design which usually has its own machine language (the way 1's and 0's are organised for it to understand). As each CPU typically understood different instruction sets, different compilers were written to "wrap" architecture-dependent code.

Now the next problem was that it's not as simple as writing the code once and compiling it for each architecture.  The code usually had to be modified for each system it was intended to run on, so portability was lost.  Having a large project would render this process impractical so a new language came along that tried to solve this problem once and for all.

Java

Java was a language developed in 1995 by what was once Sun Microsystems (now Oracle).  What's interesting about Java is that it is much more than just a language.  Java is a whole ecosystem, having the language syntax, compilers, environments, SDK and community.

Duke, the Java mascot

But how did it solve the portability issue?  As I mentioned, it is a whole ecosystem so there is a more elaborate system at play.  What Sun did was create a language that is then compiled to a byte code rather than machine code.  This byte code is then executed by the Java Virtual Machine (so, yes, it's still machine code, but a different kind of machine).  This JVM is the only part which is differently coded and compiled depending on the architecture.  

So we now have a language which can be written and compiled just once and being confident that it will run on any kind of CPU as long as the JVM exists for that CPU.  This VM is also known collectively as the Java Runtime Environment (JRE), of which the byte code interpreter plays a major role.

Along the years Java was prominent on the web in what are knowns as applets.  Nowadays with the emergence of HTML5 and JavaScript (which has a relation of 0% to Java, so don't get confused), applets have become a thing of the past.  Java is also popular on desktop applications, mobilephones, TV set top boxes, DVD players, etc.

Java today

Java has a very strong community and many standards go through what are known Java Specification Requests (JSRs ), much like Request For Comments (RFCs) if you're familiar with network protocols.  Basically this is a process for definitions of ideas, standards, protocols, etc.

Through this process, Java has become arguably one of the top languages for high end websites (technically known as web apps).  Twitter for example, runs on Java, so you get the idea of the strength of Java.  Throughout this series we shall cover, quite in depth, how to write enterprise web applications in Java.

Java used to, and still does in a revived way, dominate the mobile aspect to.  This sheer adaptability, from top range servers to mobile phones, without doubt, makes Java the most versatile language ever.  In the early days of smartphones, Symbian was the king of mobile operating systems.  It used to run a version of Java known as J2ME (Mobile Edition).  Today the Operating System with the largest active user base is Android.  Surprise surprise, apps written for this OS are also in Java and use almost the exact same tools - it's a bit more complex - but we'll see as we go along  how seamless it is to adapt your Java code to it.

Next Steps

So now you have a very basic idea of what programming is and how Java relates to it.  Of course, a lot more resources can be found elsewhere if you're interested in more history and details.  Wikipedia is one of those sites so you can head over there to further whet your appetite.

Following this post we shall start off with a basic Java environment set up; from the quick installation to your first Hello World! 

Some points on the Android UI

Android is a great OS - there's no doubt about that, even if you measure that statement using the number of active installations.  It has an interesting history, starting from plans to create an OS for digital cameras and ending up being Google's core mobile platform running on around a billion devices.  It is technically well designed, open source and very adaptable; from CPU architectures to screen sizes, Android can adapt.

Progress of Android over the years (Ars Technica)

As Android progressed to meet the expected standards of the day, the general UI got more minimalist while more colours were introduced (older versions looked darker).  Despite the move towards a more modern UI in general, it is still possible for application developers to apply their own style.  A typical result of this support was that developers of older applications did not bother updating their styles to the latest version (this is basically an XML file).

What we ended up with is a FIAT 127 in 2015's motorshow.

Not quite in the same league

The problem with this situation is that not only we have to sometimes use outdated applications, but Google is also pushing a new 'UI language'.  There is nothing wrong in having a new UI language...except when few developers are following it, and you're not one of them.  If Android is to have a uniform, clean and modern UI, there should be a mechanism which automates the transition of styles to the latest standard in cases where the default file was left lying around.  Automation is not uncommon on the Android ecosystem - Code is checked for potential errors, style files must be up to standard, even copyright issues are flagged by a bot - so why not a simple style file?

What's the deal with this UI (SIM Tool Kit)?

As I mentioned earlier, there is also another problem which Google does not seem to want to fix - Material Design.  Consistency is key in product branding and Google is/was known for their efforts in this regard.  The ubiquitous bar in all their web products and their logo in the exact same location made it clear that this is a Google product.

Nowadays, their Android apps are cacophony of UI element styles and whatnot.  Despite their efforts to make Material Design the next standard, it's already been 2 years and I have no idea when this next will be now.  It can be seen in some apps, such as the settings, and the major Google apps.  However, applications such as the Google Analytics still sport the Android 4.3 UI.  Even worse is the app for Blogger - with UI probably designed by the Romans.

Yet again, even though the apps follow the general material design, all of them seem to have a language of their own.  One aspect which was recently highlighted was the lack of consistent scrollbars.  Now we got a new scrollbar in the application launcher too, for diversity.

Google Calender app has to be one of my favourites.  It's fast, visually appealing and above all, useful.  I use it regularly to set appointments, reminders, etc. just like all other users.  The problem with the whole Calendar ecosystem is the web version.  Why has Google introduced the Material Design, implemented it correctly in Calender on Android yet left the web version in the dark while at the same time it developed the Inbox service with correct material guidelines on both Android and the web (I'm not discussing whether Inbox is practical or not)?  I understand the drive towards mobile and I truly appreciate the improved UI on mobile, but I'm not in favour of sheer inconsistency (and then again, there are web versions better than their apps).

Yes this was quite a rant - not really helpful for many.  But it gets frustrating when you're working on your services and try to follow as many guidelines as possible to make your users happy.  Thankfully apps are not accepted or rejected based on their looks and interaction, although sometimes I do favour such a system as it does improve the users' mobile experience.

Hallo!

So, hi.  Well, let's start with the basics.  I am a human named James and even though this is not the first time which I am sort of 'blogging', it still feels a bit strange.  I had a website once and I wrote some stuff over there, but it's been ages since then (the domain does not even exist any more hehe).  So recently I started thinking about being part of the 'front-end' of the internet, as I am a programmer and my contribution to the internet has been somewhat invisible, you know, not many people will look at your code, but a considerable number of people wondering around the tubes of the internet will have a look at your page during their daily hunt for lolcats.

At first I thought maybe Google+ might be helpful.  Mind you, not that it is not helpful, but it is really a micro-blogging thing, so - it's not enough.  But anyway, this Google product revolution got me curious about how things have changed and I remembered they had this free blogging service.  The new layouts are definitely a great improvement so that raised my hopes too.  Also, I did not want to spend money on hosting at the moment, so pretty much this was the best solution.

I think I started off with the basics but got lost.  Oh, well, as I said, I am James, from Malta but I am living in Germany, for now (so there is no one to pay bills, cook food etc. see why I won't pay to get my site for now? :P).  I work as a programmer, mostly using Java, and let's put it plainly, I'm not the kind of coder that uses a tonne of frameworks and stuff, mainly because I deal with rather lower level applications rather than the popular business apps.  By the way, I am also starting to code some Android apps too (Sorry applers, I'm really not a great fan of mac and stuff :P).

I hope that amounts to a proper intro, as in, you got to know my name right :D?  Well, enjoy my blog, if any of you plan to follow up or something.  If not, you can throw me in one of your circles on Google+ :D

Regards

James