Java Programmer Skills Programme

📘LESSON 2

3.1 Lesson Outcomes

After completing this lesson, learners will be able to:

Define Java programming.
Explain the history and evolution of Java.
Identify uses of Java programming.
Explain the Java platform and its components.
Differentiate between source code and machine code.
Identify Java basic syntax structures.
Explain the purpose of Eclipse IDE and Java projects.

3.2 Overview

Java is one of the world’s most widely used programming languages and is commonly used in enterprise systems, web applications, Android applications, and software development environments.

This lesson introduces learners to Java programming and explains the history, uses, platform structure, syntax, and development tools used in Java software development.

Java is widely used in:

banking systems,
enterprise applications,
Android development,
cloud computing,
and web systems.

Understanding Java programming is important because Java is widely used in modern software engineering and enterprise development.

KT0201 — Definition of Java

Java is a:

high-level,
object-oriented,
platform-independent programming language.

Java was designed to allow developers to:

write programs once,
and run them on multiple operating systems.

Characteristics of Java

Java is:

secure,
robust,
portable,
and multithreaded.

Importance of Java

Java supports:

software development,
enterprise systems,
mobile applications,
and web applications.

KT0202 — Java History and Evolvement

Java was developed by:

James Gosling

at Sun Microsystems during the early 1990s.

Java was originally called:

Oak

before being renamed Java.

Java Evolution

Year	Development
1991	Java project started
1995	Official Java release
Present	Enterprise and cloud adoption

Importance of Java Evolution

Java evolution improved:

portability,
security,
scalability,
and enterprise support.

KT0203 — Java Uses

Java is used to develop:

desktop applications,
web applications,
enterprise systems,
and Android applications.

Examples of Java Uses

Area	Example
Banking	ATM systems
Mobile Development	Android apps
Enterprise Systems	ERP systems
Web Applications	Online banking

Importance of Java Uses

Java supports:

large-scale applications,
secure systems,
and enterprise software environments.

KT0204 — Java Platform

The Java platform is the environment used to:

develop,
compile,
and execute Java programs.

Java supports:

Write Once, Run Anywhere (WORA)

Components of the Java Platform

Component	Purpose
JDK	Development tools
JVM	Executes Java bytecode
JRE	Runtime environment

Importance of the Java Platform

The Java platform supports:

portability,
software execution,
and cross-platform compatibility.

KT0205 — Java Features

Java contains several features that make it suitable for software development.

Main Java Features

Feature	Description
Platform Independent	Runs on different systems
Object-Oriented	Uses classes and objects
Secure	Provides security mechanisms
Robust	Handles errors effectively
Multithreaded	Supports concurrent tasks

Importance of Java Features

Java features improve:

application reliability,
portability,
security,
and scalability.

KT0206 — Source Code vs Machine Code

Source code is human-readable programming code written by developers.

Machine code is binary code executed by computers.

Source Code Example

System.out.println("Hello");

Machine Code Example

101010101010

Comparison

Source Code	Machine Code
Human-readable	Computer-readable
Written by programmers	Executed by processors
Easier to understand	Binary format

Importance of Source Code and Machine Code

Understanding source code and machine code helps learners understand:

compilation,
program execution,
and software processing.

KT0207 — Components of Java Platform and Respective Uses (JDK, JVM, JRE)

Java programs use several platform components during development and execution.

JDK — Java Development Kit

The JDK contains:

development tools,
compiler,
and libraries.

The JDK is used to:

write,
compile,
and develop Java applications.

JVM — Java Virtual Machine

The JVM executes Java bytecode.

The JVM allows Java programs to run on different operating systems.

JRE — Java Runtime Environment

The JRE provides:

libraries,
JVM,
and runtime support

required to run Java applications.

Comparison of Components

Component	Purpose
JDK	Development
JVM	Program execution
JRE	Runtime environment

Importance of Java Platform Components

These components support:

Java development,
compilation,
and execution.

KT0208 — Java Basic Syntax

Java syntax refers to the rules used when writing Java programs.

Basic Java Syntax Example

public class Main {

    public static void main(String[] args) {

        System.out.println("Hello World");
    }
}

Basic Syntax Elements

Element	Purpose
class	Defines a class
main()	Entry point
System.out.println()	Displays output
{}	Code block

Importance of Java Syntax

Java syntax ensures:

correct program structure,
successful compilation,
and readable code.

KT0209 — Introduction to Eclipse

Eclipse is an Integrated Development Environment (IDE) used for Java programming.

Eclipse provides tools for:

writing code,
debugging,
compiling,
and managing Java projects.

Features of Eclipse

Feature	Purpose
Code Editor	Writing code
Debugger	Finding errors
Project Explorer	Managing projects
Auto-completion	Faster coding

Importance of Eclipse

Eclipse improves:

productivity,
debugging,
and software development efficiency.

KT0210 — What is a New Java Project

A Java project is a structured collection of:

Java files,
packages,
libraries,
and resources.

A new Java project provides an organized environment for software development.

Components of a Java Project

Component	Purpose
src Folder	Stores source code
Libraries	External dependencies
Packages	Organizes classes
Class Files	Program classes

Importance of Java Projects

Java projects support:

organized development,
project management,
and software maintenance.

3.5 Key Notes / Summary

Java is a platform-independent programming language.
Java was developed by Sun Microsystems.
Java is used in enterprise, web, and mobile applications.
The Java platform includes JDK, JVM, and JRE.
Source code is human-readable code.
Machine code is computer-readable binary code.
Eclipse is a Java development IDE.
Java projects organize software development resources.