Before you start this course, you will need a PC or laptop and an editor. We all know what is a PC and laptop but may not know what a text editor is. An editor is a tool, a piece of programming software that enables you to write, run, and edit your program. You need them in this course because the course is practical and practice-based. One good thing about programming and software engineering is that most if not all the tools and materials are free, but you need to devote the time, concentration, and determination to succeed as the rewards and benefits are great.

Main Features

Introduction

Java is an open-source program and is synonymous with software, programming, and the World Wide Web.

It is a platform for developing and running applications. Some websites and applications cannot run on a desktop without Java installed on it.

Java is a popular programming language created by James Gosling when he was at Sun Microsystems (Sun) in 1991. The first version of Java was (Java 1.0) and was released in 1995. Oracle Corporation acquired Java in 2010 when they acquired Sun Microsystems.

Furthermore, it is one of the oldest languages and remains relevant up to date and remains in the top four in the world.

Cost

It is free and supported by the user communities, which are in their millions all over the world. Furthermore, it is known and recognised that over 3 billion gadgets or devices run on Java.

Creative Mind

You can do anything with Java, and there are no limits to what you can do with it with a creative mind.

Demand for Java Engineers

Java engineers are sought all over the world, you can take advantage of it.

Reliability

It is a fast, secure, reliable programming language for coding everything from mobile apps and enterprise software to big data applications and server-side technologies.

What You Can Do With Java

It can be used for Cloud Computing, A.I. Game Development, Big Data, and Web Development, Desktop apps, Server and Web Servers, etc.

Salary

The average salary of a Java Developer is around £65k.

Why Popular Choice

Quality Learning Resources

• There are high-quality books, documentation and courses.

• Easy to learn.

Functions and Libraries

• Inbuilt functions and libraries

High-Quality Development Tools

• IDEs for compiling, debugging, etc.

Security

• Is a very secure programming language.

Platform Independent

• Windows, Linux, Andriod, IOS, etc

Active User Community Support

• Open Source and free community support

Features of Java

• Object Oriented

• Portable

• Simple

• Secure

• Dynamic

• Distributed

• Multithreading

• Two staged execution (complied and interpret).

How it works!

The program is a means to communicate with the machine. Machine hardware only responds to codes which are electronic communication. Which acts as the bridge! Therefore we need:

a. Java language and APIs

Here the programmer writes the code  and the machine:

1. Compiler – compiles the source code

2. Interpreter – interprets it into byte-code

b. Java Virtual Machine

As the code is translated into bytecode, it can then be run in the JVM.

The bytecode is the language between the low-level language and high-level language and is responsible for making Java platform independent.

Implementation of Java

Java source code is compiled by the compiler (.javac) and translated into the bytecode which is, in turn, interpreted by the Java Virtual machine (JVM).

The instructions are stored in .class files and are executed by the Java Virtual Machine.

Java Platforms

There are four types:

• Standard Edition(Java SE),

• Enterprise Edition(Java EE),

• Micro Edition(Java ME), and

• Java FX.

 

To get started

Most computers and laptops come in handy or are ready with Java installed. To make sure Java is already installed, you can type ‘Java -version’ on a command line or terminal, and it will show you whether Java is installed and the version.

The output will look like this:

OpenJDK version “11.0.10” 2021-01-19

OpenJDK Runtime Environment (build 11.0.10+9-Ubuntu-0ubuntu1.20.04)

OpenJDK 64-Bit Server VM (build 11.0.10+9-Ubuntu-0ubuntu1.20.04, mixed mode, sharing).

My output looks this way because I am using Linux. If you are using Windows or macOS, yours will be the same but will look slightly different because of your system.

But if it is not installed – go to java se – downloads oracle technology network oracle

 

How to Develop Java Program

Setting up the environment

JDK

To set up the Java Development Environment, we need JDK, JRE and the JVM.  We also need the JIT Compiler.  They are the core technologies we will require to be able to write, compile and run the Java program. Now let us look at these technologies separately and see how they work with each other:

JDK  – Java Development Kit

This kit is platform specific and that is why we have versions for Mac, Windows, Linux, etc.

It holds tools, binaries, and executables required for compiling, debugging and executing the Java Program. The JDK also contain the JRE and JVM. It can be downloaded from the Oracle website.

JRE – Java Runtime Environment

JRE is the subset of the JDK. It consists of the JVM, binaries and classes to successfully execute the Java programs. It is only a platform to run the program and not a complete development environment.

JVM – Java Virtual Machine

The JVM is at the core of Java Programming. It compiles the source code and converts it to machine-readable form which is the bytecode. The JVM act as an interface between machines and operating systems enabling programs developed in other machines or operating systems to run making them platform-independent. It is also responsible for security, memory management and garbage collection.

JIT – Just In Time Compiler

It is part of the JVM that converts the bytecode to a specific machine code or language.

 

 

 

 

 

 

Content

Java Introduction
Choice of IDE
Java Syntax
Java Variables
Java Data types
Java Comments
Java String
Java Maths