☕ Java

Java Tutorial

Java is a statically typed, object-oriented language that runs on the JVM. It is widely used for backend services, enterprise systems and Android, and it is the language Spring Boot is built on.

This tutorial starts with installing the JDK and writing your first program, then moves through the core language, object-oriented design, strings, exceptions, collections, generics, multithreading, I/O and NIO, the functional features introduced in Java 8, newer language features up to Java 21, the Date Time API and JDBC. Each lesson explains the idea in plain terms and follows it with code you can run.

Suggested learning path

Introduction and Java Basics: set up the JDK, learn variables, types and operators.
Control Statements, Arrays and Strings: write real programs with loops and text handling.
Object-Oriented Programming and Exception Handling: classes, inheritance, interfaces, error handling.
Collections Framework and Generics: the data structures used in almost every Java project.
Java 8 Features and Functional Programming: lambdas, streams and Optional.
Multithreading, I/O and JDBC: concurrency, files and databases.

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All sections

19 sections, 315 lessons.

Java Tutorial

Suggested learning path

All sections

Introduction

Java Basics

Control Statements

Object-Oriented Programming

Arrays

Strings

Exception Handling

Packages and Access Control

Java Memory Management

Collections Framework

Generics

Multithreading

Java I/O

Java NIO

Java 8 Features

Java 9 to 21 Features

Functional Programming

Date Time API

Java Database Connectivity (JDBC)