Learn Java

Coming Soon

Enterprise backends, Android, and distributed systems

Java Spring Boot Android Enterprise

Coming Soon

The language that runs half the world’s enterprise software. Backend (Spring Boot), Android development, distributed systems, and cloud infrastructure — Java’s ecosystem is massive and battle-tested.

This course covers modern Java from fundamentals through Spring Boot microservices and Android app development.

Start Here — Learning Roadmap

A suggested path from zero to mastery. Follow these steps in order:

Learn Java Fundamentals — Start with syntax, data types, control flow, arrays, and OOP (classes, inheritance, interfaces) using MOOC.fi or Oracle tutorials
Practice with Small Programs — Build console apps to master collections, generics, streams, file I/O, and exception handling
Understand Build Tools — Learn Maven or Gradle for dependency management, project structure, and build automation
Study Design Patterns — Learn common patterns (Factory, Observer, Strategy, Builder) through Java Design Patterns and Effective Java
Learn Spring Boot — Build REST APIs with Spring Boot, understand dependency injection, Spring Data JPA, and Spring Security
Master Database Access — Use JPA/Hibernate for ORM, write JPQL queries, understand connection pooling and transactions
Build Microservices — Create distributed systems with Spring Cloud, message queues, and container orchestration
Write Tests — Learn JUnit 5, Mockito, TestContainers, and integration testing patterns
Explore Modern Java — Use records, sealed classes, pattern matching, virtual threads, and other post-Java-17 features
Deploy & Monitor — Containerize with Docker, deploy to Kubernetes or cloud platforms, implement observability

Official & Core Documentation

Oracle Java Tutorials — Comprehensive official tutorials covering language basics through advanced topics (Beginner)
Java SE API Documentation — Complete API reference for the Java standard library (All levels)
dev.java — Official Java developer community portal from Oracle with guides and tutorials (Beginner)
Spring Boot Guides — Hands-on quickstart guides for building Spring Boot applications (Intermediate)
Spring Boot Reference Documentation — Official reference for the most popular Java framework (Intermediate)
Android Developer Guides — Official Android development documentation and best practices (Intermediate)
OpenJDK — The open-source reference implementation of the Java platform (Advanced)
Java Roadmap — Community-created visual roadmap for Java developers (Beginner)
Spring Boot Roadmap — Step-by-step guide to becoming a Spring Boot developer (Intermediate)

GitHub Awesome Lists & Curated Collections

awesome-java — Comprehensive curated list of Java frameworks, libraries, and software organized by category
awesome-spring — Curated list of books, tutorials, courses, and resources for the Spring framework ecosystem
awesome-spring-boot — Curated list of blogs, tutorials, courses, and resources for Spring Boot
awesome-java-security — Curated list of Java security resources, tools, and libraries
java-design-patterns — Design patterns implemented in Java, the most starred Java repo on GitHub
awesome-microservices — Curated list of microservice architecture resources applicable to Java/Spring

Interactive Courses & Hands-On Platforms

Free Courses

MOOC.fi Java Programming — University of Helsinki’s free, comprehensive Java course, widely considered the best free option (Beginner)
CodingBat Java — Free practice problems for Java fundamentals and string/array logic (Beginner)
Java Design Patterns — Open-source catalog of design patterns implemented in Java (Intermediate)
Baeldung — Thousands of free tutorials on Java, Spring, and related technologies (All levels)

University & MOOC Courses

JetBrains Academy — Java — Project-based Java learning with real-world applications (Beginner, Paid)
Codecademy Learn Java — Interactive beginner course with in-browser coding (Beginner, Paid)
Coursera — Object Oriented Programming in Java (Duke) — Free-to-audit university specialization (Intermediate)
MIT OpenCourseWare — Intro to Programming in Java — MIT’s free introductory Java course (Beginner)

Practice & Challenges

Exercism Java Track — Mentored coding exercises with community feedback (Beginner)
Codewars Java — Thousands of coding challenges from beginner to expert level (All levels)
LeetCode — Algorithm and data structure challenges with Java support, widely used for interview prep (Intermediate)
HackerRank Java — Java-specific practice problems and certification (Beginner)
Advent of Code — Annual coding puzzles, popular for practicing Java problem-solving (Intermediate)
Project Euler — Mathematical programming challenges solvable with Java (Intermediate)

Video Courses & YouTube Channels

Structured Course Playlists

freeCodeCamp — Java Full Course — Comprehensive free Java course on YouTube (Beginner)
Amigoscode — Spring Boot Tutorial — Complete Spring Boot full course (Intermediate)
Java Brains — Spring Framework — Clear Spring framework and Java concept tutorials (Intermediate)

Individual Creators & Channels

Coding with John — Concise, clear Java concept explanations with visual aids (Beginner)
Amigoscode — Modern Java, Spring Boot, and full-stack content with real projects (Intermediate)
Dan Vega — Spring Boot, Java, and modern development practices (Intermediate)
Marco Behler — Practical Java and Spring explanations with production context (Intermediate)
Telusko — Java and Spring Boot tutorials for beginners and intermediate developers (Beginner)
Java Guides — Spring Boot, Microservices, and React full-stack tutorials (Intermediate)
SivaLabs — Spring Boot, Docker, and cloud-native Java development (Advanced)
Laur Spilca — Spring Security and Spring framework deep dives (Intermediate)
in28minutes — Spring Boot microservices, Docker, and Kubernetes tutorials (Beginner)

Books & Long-Form Reading

Free Online Books

Think Java — Free introduction to computer science and programming using Java (Beginner)
Java Notes for Professionals — Free reference compiled from Stack Overflow documentation (All levels)
Spring Boot Reference Guide — Complete free reference documentation (Intermediate)
Introduction to Programming Using Java — David Eck’s free comprehensive textbook covering Java from basics to advanced (Beginner)
Java, Java, Java (Morelli) — Free interactive Java textbook with embedded exercises (Beginner)

Essential Paid Books

Effective Java — Joshua Bloch’s essential Java best practices, the must-read for every Java developer (Intermediate, Paid)
Head First Java — Visual, hands-on introduction to Java programming (Beginner, Paid)
Modern Java in Action — Lambdas, streams, functional patterns, and reactive programming (Intermediate, Paid)
Java Concurrency in Practice — Brian Goetz’s definitive guide to writing thread-safe Java code (Advanced, Paid)
Spring in Action — Comprehensive guide to the Spring ecosystem (Intermediate, Paid)
Clean Code — Robert C. Martin’s principles of writing readable, maintainable code with Java examples (Intermediate, Paid)

Community, Practice & News

Forums & Discussion

r/java — Active Reddit community for Java news and discussion
r/learnjava — Beginner-friendly subreddit for Java learners
Stack Overflow — Java — The largest Q&A archive for Java questions
dev.java Community — Official Java developer community from Oracle

Newsletters & Blogs

Baeldung Java Weekly — Weekly guide to the main Java and Spring developments
Java Annotated Monthly (JetBrains) — Monthly roundup of Java and JVM news from JetBrains
Inside Java — Official blog from the Java team at Oracle with deep dives on language features
InfoQ Java — Java news, trends, and expert articles from the developer community

Package Registries & Ecosystems

Maven Central — Central repository for discovering Java libraries and dependencies
Spring Initializr — Quickly bootstrap Spring Boot projects with selected dependencies
Gradle Plugin Portal — Discover and share Gradle build plugins

Tools & Environments

IntelliJ IDEA — The most popular Java IDE with unmatched refactoring and code intelligence (Community edition is free)
VS Code + Extension Pack for Java — Lightweight editor with Java support via Microsoft’s extension pack
JShell — Java’s built-in REPL for interactive experimentation
JMH (Java Microbenchmark Harness) — Official OpenJDK benchmarking framework
VisualVM — Visual tool for monitoring, troubleshooting, and profiling Java applications
Jib — Build optimized Docker images for Java applications without a Dockerfile
SonarQube — Static analysis tool for code quality and security in Java projects
GraalVM — High-performance runtime for Java with native image compilation and polyglot support
Spring Initializr — Web-based Spring Boot project generator with dependency selection
jenv — Manage multiple JDK versions on your development machine
SDKMAN — Software Development Kit Manager for managing parallel JDK versions and Java tools