An introduction in Java for beginners and enthusiasts who want to get into the software industry.
Every large company from Facebook to Google uses Java in some form or another to build their services. It is an extremely old language and has a great amount of history behind it. To give you an idea, a young man named James Gosling, who held a PhD in Computer Science from Carnegie Mellon, was working at Sun Microsystems. He created the language while he was working on a project to develop interactive television along with his team, known as the ‘Green Team’. The product that they ended up creating was too complex for television and ultimately, that project is now known as Java. Currently, Java is used in websites, mobile phone applications, gaming, E-commerce and a lot more!
The motivation as to why should one learn java is profound. For starters, Java is very easy to learn. Coding in java is very rigid in the sense that, semicolons are very important and we need to use data types while defining a variable, but once you get over these small hiccups, you’ll realize that it’s quite easy. Besides this Java is also object-oriented. By this, we mean that we create objects of a class to access the functions and variables within that class. This concept is followed by almost every other programming language and it makes our code reusable, to the entire Java community. So, once you familiarize yourself with the logic behind object-oriented programming, you can smoothly bifurcate into any other language.
Another great advantage of java is that it is, platform-independent, which means that code written and complied on one computer, needn’t be compiled once again when you need to run it on a different computer. This makes a significant difference as running an application on another computer is very easy, you can just download a java application from the World Wide Web and run it, as long as your computer has a Java Virtual Machine(JVM) installed.
Features of java
The reason why Java shines brighter than any other language is because of its security and portability.
Robust: With the word robust we are implying that Java has strong memory management and the fact that it does not use pointers deals with the security problems. Java also has an automatic garbage collector whose task is to collect objects that are not being used in a Java Application and throw those objects away. Java has impressive classes to handle the exception when they occur, as well as, a great type checking mechanism.
Security: Java has an exceptional security system that does not entertain any viruses and is a temper-free system. Java barely interacts with the Operating System because java applications run on the JVM, unlike C++ which greatly interacts with the OS. So, any viruses that may be deployed only affect the JVM and the OS is safe. It also has a bytecode verifier which checks for illegal code, if any are found, it doesn’t permit the object access rights.
Multi-Threaded: A thread is what we use when we’re executing a program. Java can run multiple threads at the same time while it is executing a single program and the best part about this is that every thread doesn’t take up new memory space, they occupy a common memory location. So we can use the internet and watch videos all at the same time.
How does java run on our computers?
Java has 3 components that make it highly secure, and portable which are the Java Virtual Machine, the Java Runtime Environment and Java Development Kit. All three work together in unison to compile the source code and run it on any machine. The protocols which it follows is known as the Java Architecture. Let us explore the components in finer detail.
Java Virtual Machine(JVM): This is the first stage of the architecture. We write code which is known as the source code which is then loaded into the JVM. Once that is done it verifies the code and then executes it. After that, the source code is passed on to the JRE. The JVM is what makes it possible to write code once and then run it anywhere on any machine.
Java Runtime Environment(JRE): While coding we tend to use pre-existing functions that already exist in the Java libraries. All these libraries that are required for our software to run are stored in the JRE.
Java Development Kit (JDK): As its name suggests, it is a package that we use when we want to develop applets. It is filled with a lot of features and the JRE is part of the JDK.
Java also uses a Just-In-Time compiler at runtime which Is included in the JVM. This job of a JIT compiler in java is to convert the Bytecode, which can be read by the JVM, into the machines native code, which can then finally be executed on a machine. This conversion is not done beforehand and is done at runtime, which makes execution a bit slower.
Now, if you’re a beginner and would like to move upwards, you will need to start working on projects. There are all kinds of projects ranging in difficulty available online, but you need to look for projects in java for beginners. Working on projects forces you to read the work of other developers. Doing this helps you discover new functionalities which otherwise you may have been oblivious to. Here are some projects in java for beginners to help you get started.
Learning how to code can be very scary at the beginning and you are bound to feel lost when you are lost in a sea of errors to which you can’t find a solution, but that is when you stick with it and ask the community for help. Pretty soon the sea would have calmed itself and you will find yourself sailing smoothly as a Java developer.