Java Tutorial Roadmap

Introduction to Java

Overview of Java

Java is a high-level, object-oriented, platform-independent programming language widely used for building enterprise applications, web applications, mobile apps, and backend systems.

Java vs C++ vs Python

• Java: Platform-independent, OOP-focused, strong memory management
• C++: High performance, low-level memory control
• Python: Simple syntax, rapid development, scripting-friendly

Java Platform and Execution

• Just-In-Time (JIT) Compiler
• Difference between JIT and JVM
• Bytecode vs Machine Code
• How Java achieves platform independence

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Java Basic Concepts

Java Basic Syntax

• Structure of a Java program
• Writing a Hello World program

Data Types in Java

• Primitive data types
• Object (reference) data types

Identifiers

• Java identifier naming rules

Variables in Java

• Variable declaration and initialization
• Scope of variables

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Input and Output in Java

Console Input

• Taking user input in Java
• Scanner class
• Different ways to read input from the console

Output in Java

• Using System.out.println()
• Formatted output using printf()

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Operators in Java

Types of Operators

• Unary operators
• Assignment operators
• Relational operators
• Logical operators
• Ternary operator

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Flow Control in Java

Decision-Making Statements

• if statement
• if-else statement
• if-else-if ladder

Loops

• while loop
• do-while loop
• for-each loop

Control Statements

• break statement
• continue statement
• return keyword

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Arrays in Java

Arrays Overview

• Declaring and initializing arrays

Types of Arrays

• One-dimensional arrays
• Multidimensional arrays
• Jagged arrays
• Final arrays

Arrays Utility Classes

• Arrays class
• reflect.Array
• Difference between util.Arrays and reflect.Array

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Object-Oriented Programming (OOP) in Java

Java Naming Conventions

• Class, method, and variable naming rules

Classes and Objects

• Understanding classes and objects
• Object class in Java
• Singleton design pattern

Constructors

• Default and parameterized constructors
• Copy constructor
• Constructor overloading
• Constructor chaining
• Private constructors and singleton classes

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Inheritance in Java

Inheritance Concepts

• Inheritance and constructors
• Types of inheritance
• Interfaces and inheritance

Multiple Inheritance

• Achieved using interfaces

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Abstraction in Java

Abstraction Concepts

• Abstract classes
• Abstract methods
• Control abstraction

Data Hiding vs Abstraction

• Key differences

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Encapsulation in Java

Encapsulation Concepts

• Data hiding using access modifiers

Abstraction vs Encapsulation

• Key differences and use cases

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Polymorphism in Java

Polymorphism Concepts

• Compile-time polymorphism
• Runtime polymorphism

Dynamic Method Dispatch

• Method overriding

Inheritance vs Polymorphism

• Conceptual differences

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Methods in Java

Methods Overview

• Defining and calling methods

Method Overloading

• Compile-time polymorphism

Method Overriding

• Runtime polymorphism

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Memory Management in Java

Memory Allocation

• Stack vs Heap memory

JVM Memory Areas

• Types of memory areas allocated by JVM

Garbage Collection

• Garbage collection basics
• Types of JVM garbage collectors

Memory Leaks

• Causes and prevention

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Java Virtual Machine (JVM)

JVM Stack Area

• Stack frames and execution

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Wrapper Classes

Wrapper Classes Overview

• Character class
• Byte, Short, Long, Float classes

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Keywords in Java

Java Keywords

• List of Java keywords

Important Keywords

• super
• final
• static
• enum
• transient
• volatile

final vs finally vs finalize

• Differences and use cases

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Access Modifiers

Types of Access Modifiers

• Public
• Protected
• Package-private
• Private

Access vs Non-Access Modifiers

• Key differences

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Inner Classes in Java

Inner Class Concepts

• Types of inner classes

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Packages in Java

Package Basics

• Creating packages

Common Packages

• java.util
• java.lang
• java.io

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Exception Handling in Java

Exception Basics

• Types of exceptions
• Checked vs unchecked exceptions

Exception Handling Mechanism

• try, catch, finally
• Flow control in exception handling

throw and throws

• Custom exception handling

Advanced Exception Topics

• User-defined exceptions
• Chained exceptions

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Multithreading in Java

Thread Basics

• Lifecycle and states of a thread
• Main thread

Thread Creation

• Thread class
• Runnable interface

Thread Management

• Thread priority
• Naming threads
• start() method behavior

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Synchronization and Concurrency

Thread Synchronization

• Importance of synchronization
• Method-level and block-level synchronization

Locks and Concurrency

• Lock framework vs synchronization
• Atomic vs volatile vs synchronized

Deadlocks

• Deadlock concepts
• Prevention and avoidance

Advanced Locks

• Lock vs monitor
• ReentrantLock

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File Handling in Java

File Handling Basics

• File class
• Creating files

Reading Files

• Different ways to read text files

Writing Files

• Writing data into files
• FileWriter class

File Operations

• Deleting files
• File permissions

Advanced File Handling

• FileDescriptor
• RandomAccessFile