Java Programming Fundamentals

What is Java?

• Java is a high-level, object-oriented programming language developed by Sun Microsystems (now owned by Oracle Corporation)
• Designed to have as few implementation dependencies as possible, allowing Java code to run on any platform that has a Java Virtual Machine (JVM)

Key Features

• Platform Independence: Java code can run on any platform that has a JVM, making it "write once, run anywhere"
• Object-Oriented: Java is based on object-oriented programming (OOP) concepts, such as encapsulation, inheritance, and polymorphism
• Simple and Familiar Syntax: Java's syntax is based on C++ and is easy to learn for developers familiar with C-style languages
• Robust Security: Java has built-in security features, such as memory management and data encryption, to ensure secure coding practices

Java Virtual Machine (JVM)

• Runtime Environment: The JVM is responsible for executing Java bytecode on a computer
• Bytecode: Java code is compiled into an intermediate form called bytecode, which can be run on any JVM
• Platform-Independent: The JVM provides a layer of abstraction between the Java code and the underlying platform, allowing Java code to run on any platform

Java Development Kit (JDK)

• Bundle of Tools: The JDK includes a set of tools for developing, debugging, and testing Java applications
• Java Compiler (javac): Compiles Java source code into bytecode
• Java Runtime Environment (JRE): Includes the JVM, libraries, and utilities for running Java applications
• Development Tools: Includes tools like jar, javadoc, and jdb for packaging, documenting, and debugging Java applications

Java Editions

• Java SE (Standard Edition): Designed for developing desktop applications, provides a set of libraries and APIs for building GUI applications
• Java EE (Enterprise Edition): Designed for developing enterprise-level applications, provides a set of libraries and APIs for building web applications and services
• Java ME (Micro Edition): Designed for developing applications for mobile devices and embedded systems

Java Applications

• Android Apps: Java is used to develop Android apps, with the Android SDK providing a set of libraries and tools for building Android applications
• Web Applications: Java is used to develop web applications, with frameworks like Spring and Hibernate providing a set of libraries and tools for building web applications
• Desktop Applications: Java is used to develop desktop applications, with libraries like Swing and JavaFX providing a set of APIs for building GUI applications