Ehis Edemakhiota

Posted on Mar 18

Java Study Group: Motivation, Roadmap and Goals

#java

Hi there!

My name is Ehis Edemakhiota and I’m excited to see that you’ve come here. I am a Software Engineer and Java is my first language- I have been writing Java for about 5 years. I enjoy writing and thinking in Java because it is structured, dependable and if understood well, can be used to build software that is scalable and reliable. I want to be like Java :).

A famous quote says: "if you want to go quickly then go alone, but if you want to go far then go with people" . I want to go far and I want to do so with you :). This is my motivation for starting this study group.

The goal of the study group is for beginner to expert level Java programmers to in 8-12 weeks be able to:

build production-ready Spring Boot applications,
be prepared for Java/ Spring Boot technical interviews,
contribute to real-world backend projects.

The topics of interest are:

Introduction to Java and Java control structures
Introduction to OOP and SOLID principles
Design Patterns
Java Arrays and Data structures
Functional programming in Java
Java concurrency
JVM Internals
Introduction to Spring Boot
Spring Boot persistence best practices
Spring Security
Logging and Observability in Spring Boot
Project Loom- Java 21 Virtual Threads
Problem solving with LeetCode

Some of the study materials include:

Spring Boot in Action
Spring Boot Up and Running
Spring Persistence Best Practices.
Relevant Medium and Baeldung.com articles
Articles from the Offical Spring documentation

Java & Spring Boot — 12-Week Study Group Roadmap

Format: 4 phases · 12 weekly sessions · Mixed levels (Beginner → Expert)

Goals: Build production-ready Spring Boot applications · Ace Java/Spring Boot interviews · Contribute to real-world backend projects

Overview

Phase	Title	Weeks	Focus
1	Java Foundations	1–3	Core Java syntax, OOP, Design Patterns + LeetCode
2	Advanced Java	4–6	Data Structures, Functional Programming, Concurrency
3	JVM & Spring Boot	7–9	JVM Internals, Spring Boot Core, Persistence
4	Production-Ready	10–12	Security, Observability, Project Loom, Capstone

Study Materials

Spring Boot in Action — Craig Walls
Spring Boot Up and Running — Mark Heckler
Spring Persistence Best Practices
Relevant articles from Baeldung.com
Relevant articles from Medium.com
Official Spring Documentation

Phase 1 — Java Foundations (Weeks 1–3)

On-ramp for beginners while giving intermediates a chance to solidify fundamentals. LeetCode problems are embedded in each session to immediately apply concepts.

Week 1 — Introduction to Java

Level: Beginner

Subtitle: Setup, syntax, control flow & LeetCode warm-up

Learning Goal

Write basic Java programs, understand primitive types, operators, and control-flow structures. Begin applying these immediately through easy LeetCode problems.

Key Concepts

JDK / JRE setup
Primitive types
Operators
if / else / switch
for / while / do-while
Methods & scope
String basics

Study Materials

Baeldung: Java Basics series
Official Java SE documentation
Medium: Java 101 for beginners
LeetCode: Explore — Java card

LeetCode Practice

Focus: Basic loops, conditionals & arithmetic. Solve in Java; submit and read other Java solutions.

Problem	Difficulty
1. Two Sum	Easy
9. Palindrome Number	Easy
13. Roman to Integer	Easy
412. Fizz Buzz	Easy
1342. Number of Steps to Zero	Easy

Week 2 — OOP & SOLID Principles

Level: Beginner

Subtitle: Classes, inheritance, interfaces & modelling kata

Learning Goal

Design Java classes using core OOP concepts, apply SOLID principles, and model solutions to LeetCode problems as well-structured classes.

Key Concepts

Classes & Objects
Constructors
Inheritance & super
Polymorphism
Interfaces & abstraction
Encapsulation
SOLID principles (S, O, L, I, D)

Study Materials

Baeldung: Java OOP guide
Medium: SOLID principles in Java
Official Java Docs: OOP trail
LeetCode: OOP-friendly problems list

LeetCode Practice

Focus: Model your solution as a class first, then implement. Practice naming and responsibility separation.

Problem	Difficulty
155. Min Stack	Medium
146. LRU Cache	Medium
706. Design HashMap	Easy
232. Implement Queue using Stacks	Easy
303. Range Sum Query — Immutable	Easy

Week 3 — Design Patterns

Level: Intermediate

Subtitle: GoF creational, structural, behavioural & pattern-recognition kata

Learning Goal

Recognise and apply common GoF design patterns; spot patterns inside LeetCode problem structures and justify your pattern choice.

Key Concepts

Singleton
Factory / Abstract Factory
Builder
Observer
Strategy
Decorator
Facade

Study Materials

Baeldung: Design Patterns in Java
Refactoring.guru pattern catalogue
Medium: GoF patterns explained
LeetCode: Patterns in coding problems (Medium article)

LeetCode Practice

Focus: Identify which GoF pattern maps to the problem structure before coding. Discuss your choice with the group.

Problem	Difficulty
284. Peeking Iterator	Medium
341. Flatten Nested List Iterator	Medium
460. LFU Cache	Medium
716. Max Stack	Medium
1603. Design Parking System	Easy

Phase 2 — Advanced Java (Weeks 4–6)

Raises the ceiling with Collections, the Streams/Lambda API, and Concurrency — high-frequency interview topics and prerequisites for understanding Spring Boot internals.

Week 4 — Arrays & Data Structures

Level: Intermediate

Subtitle: Collections framework & Big-O

Learning Goal

Select the right Java data structure for a problem and understand time & space complexity trade-offs.

Key Concepts

Arrays & multi-dimensional arrays
ArrayList / LinkedList
HashMap / TreeMap
HashSet / TreeSet
Queue / Deque / Stack
Big-O analysis

Study Materials

Baeldung: Java Collections guide
Official Java Docs: Collections framework
Medium: Data structures in Java

Week 5 — Functional Programming in Java

Level: Intermediate

Subtitle: Streams, lambdas & Optional

Learning Goal

Write idiomatic functional-style Java using the Streams API, lambdas, and method references.

Key Concepts

Lambda expressions
Functional interfaces
Stream API (map / filter / reduce)
Collectors
Optional<T>
Method references
Parallel streams

Study Materials

Baeldung: Java 8 Streams series
Official Java Docs: Stream API
Baeldung: Guide to Optional

Week 6 — Java Concurrency

Level: Advanced

Subtitle: Threads, locks & CompletableFuture

Learning Goal

Write thread-safe concurrent Java programs and use modern concurrency utilities effectively.

Key Concepts

Thread lifecycle
synchronized & volatile
ExecutorService / thread pools
Callable & Future
CompletableFuture
ReentrantLock
java.util.concurrent package

Study Materials

Baeldung: Java Concurrency series
Official Java Docs: Concurrency utilities
Medium: CompletableFuture deep dive

Phase 3 — JVM & Spring Boot (Weeks 7–9)

Opens with JVM internals so developers understand why their Spring apps behave the way they do, then moves into Spring Boot core and persistence.

Week 7 — JVM Internals

Level: Advanced

Subtitle: Memory model, GC & class loading

Learning Goal

Understand JVM architecture in depth to profile, tune, and diagnose Java applications in production.

Key Concepts

ClassLoader subsystem
Heap / Stack / Metaspace
GC algorithms (G1, ZGC, Shenandoah)
JIT compilation
JVM tuning flags
JFR / VisualVM profiling

Study Materials

Baeldung: JVM Internals series
Medium: Deep dive into the JVM
Official JVM specification

Week 8 — Introduction to Spring Boot

Level: Beginner

Subtitle: Auto-config, DI & REST APIs

Learning Goal

Bootstrap a Spring Boot project and build a functional REST API, understanding auto-configuration and dependency injection.

Key Concepts

Spring IoC container
Dependency injection
Auto-configuration
Spring Boot starters
@RestController / @Service
application.yml & profiles

Study Materials

Spring Boot in Action — Craig Walls
Spring Boot Up and Running — Mark Heckler
Official spring.io documentation

Week 9 — Spring Persistence

Level: Intermediate

Subtitle: Spring Data JPA, transactions & optimisation

Learning Goal

Implement a robust, optimised persistence layer with Spring Data JPA and handle transactions correctly.

Key Concepts

Spring Data JPA repositories
Entity mapping & relationships
JPQL & native queries
N+1 problem & fetch strategies
Transaction management
Flyway / Liquibase migrations

Study Materials

Spring Persistence Best Practices (book)
Baeldung: Spring Data JPA series
Official Spring Data JPA docs

Phase 4 — Production-Ready (Weeks 10–12)

Covers the operational concerns real teams care about: security, observability, and modern concurrency with Project Loom.

Week 10 — Spring Security

Level: Intermediate

Subtitle: Authentication, JWT & OAuth2

Learning Goal

Secure a Spring Boot application using JWT, OAuth2, and method-level authorisation.

Key Concepts

Security filter chain
UserDetailsService
JWT authentication
OAuth2 / OpenID Connect
Role-based access control
@PreAuthorize / @Secured

Study Materials

Spring Boot Up and Running — Ch. Security
Baeldung: Spring Security series
Official Spring Security reference docs

Week 11 — Logging & Observability

Level: Intermediate

Subtitle: Structured logs, metrics & tracing

Learning Goal

Instrument a Spring Boot app for full production observability: structured logs, metrics, and distributed traces.

Key Concepts

SLF4J / Logback configuration
Structured / JSON logging
Spring Boot Actuator
Micrometer metrics
OpenTelemetry tracing
Grafana / Prometheus integration

Study Materials

Baeldung: Spring Boot logging guide
Official Spring Actuator docs
Medium: Observability in Spring Boot
OpenTelemetry Java docs

Week 12 — Project Loom & Capstone

Level: Advanced

Subtitle: Virtual threads + final project

Learning Goal

Understand Project Loom, migrate to virtual threads, and deliver a capstone production-ready Spring Boot project.

Key Concepts

Virtual threads (JEP 444)
Structured concurrency (JEP 453)
Thread-per-request model
Performance benchmarking
Loom + Spring Boot integration
Capstone project presentation

Study Materials

JEP 444: Virtual Threads specification
Baeldung: Project Loom guide
Official Spring Docs: Virtual threads
Medium: Spring Boot + Project Loom

Format of each session

90–120 minutes per session — 20 min concept review, live coding exercise, then group discussion.
Beginners with intermediates during coding exercises. Experts take ownership of advanced weeks (6, 7, 12) as lead facilitators.
Where applicable, the last 20–30 minutes of each Phase 1 session for a live group LeetCode walk-through where one member screen-shares and others review the solution.
Where applicable, before live coding include a Design Patterns Kata: "Which GoF pattern does this problem smell like, and why?"
Capstone Project: Members of the study group will be paired. Each pair will work together to ship a small but complete production-grade Spring Boot application demonstrating persistence, security, and observability.

If this feels like you and you can commit for the duration of the study group, then I invite you to join me on this journey. Let's go far and grow deep together.

Cheers!