J
JavaCraft

Beginner to advanced Java ecosystem guide

Learn the Java Ecosystem
with practical, focused tutorials.

From Core Java to Spring Boot, microservices, testing, and deployment – bite-sized guides written for real-world backend developers.

Start with Java Basics View Roadmap
☕ Java · Spring Boot · Microservices

Featured Topics

Core Java

OOP, collections, streams, generics, best practices.

Spring Boot

REST APIs, security, data access, profiles.

Microservices

Service design, config, discovery, resilience.

Tools & Build

Maven, Gradle, IntelliJ, Docker basics.

Quick Start Idea

Start a “Core Java from Scratch” series: variables, control flow, OOP, collections, streams, then jump into a small Spring Boot REST API project using what you learned.

Start with the basics

View all basics →
Core Java

Java Syntax & Data Types – A Gentle Introduction

Learn how the JVM sees your code, primitive vs reference types, and how to avoid common pitfalls as a beginner.

5 min read Read
Collections

List, Set, Map – When to Use Which?

A practical explanation of Java collections with real backend examples and tips.

8 min read Read
Spring Boot

Spring Boot Project Structure – Beginner Guide

Understand controllers, services, repositories, and how to organize a clean project.

7 min read Read

Java Developer Roadmap

From absolute beginner to Spring Boot & microservices

Stage 1 · Beginner

Core Java foundations

  • ✅ Learn Java syntax & data types
  • ✅ Practice variables, if/else, loops
  • ✅ Understand methods & parameters
  • ✅ Learn OOP: class, object, this, constructor
  • ✅ Get comfortable with arrays & basic problems

Goal: Be able to write small console programs on your own.

Stage 2 · Intermediate

Modern Java & backend basics

  • ✅ Learn Collections: List, Set, Map
  • ✅ Practice exceptions & error handling
  • ✅ Learn Java 8+ features: streams, lambdas
  • ✅ Start with Spring Boot REST APIs
  • ✅ Connect Spring Boot to a database (JPA/Hibernate)

Goal: Build a simple CRUD REST API with a database.

Stage 3 · Advanced

Production & microservices

  • ✅ Learn layered architecture (controller/service/repo)
  • ✅ Add validation, DTOs, and error responses
  • ✅ Explore Spring Security & JWT basics
  • ✅ Learn microservices concepts (gateway, config, discovery)
  • ✅ Containerize apps with Docker & basic deployment

Goal: Understand how real-world Java backends are built & deployed.

Over time, each roadmap step can link to a dedicated article (for example: data types → “Java Syntax & Data Types” post, Collections → “List, Set, Map Explained”, etc.).

Latest articles

View all →
Spring Boot Nov 20, 2025 • 10 min read

Building Your First REST API with Spring Boot

Step-by-step guide to wiring controllers, services, repositories, and testing your API.

Read article →
Core Java Nov 17, 2025 • 8 min read

Java Collections – List, Set, Map Explained

Understand the difference between Lists, Sets, and Maps with examples.

Read article →
Architecture Nov 14, 2025 • 9 min read

Microservices Architecture Overview

High-level overview of gateways, registries, config servers, and service design.

Read article →

About this blog

This blog is focused on the Java ecosystem – written from the perspective of a backend developer learning and building real projects. Expect no theory-only fluff: each concept will be connected to a practical use case.

Tech stack: Java, Spring Boot, PostgreSQL, Docker, plus frontend frameworks where needed.