Core Java — The Language Track
Ten modules. From “is Java installed?” to a working CLI project that becomes the seed of your Spring Boot API. This is the foundation everything else in the sprint stands on — Spring, DSA, system design all assume the things taught here.
How This Track Works
Every module has the same skeleton, on purpose:
| Section | What it’s for |
|---|---|
| The Goal | What you can do at the end — read it first, it primes your brain |
| The Lesson | The actual teaching — diagrams, code, mental models |
| Build This | You type, you run, you break it. Non-negotiable. |
| Where / How to Practice | Free places to drill it, and the rules of practice |
| Check Yourself | Recall questions — answer WITHOUT looking. This is the learning. |
| Still Unclear? | Exact prompts to ask Claude when something won’t click |
| Add to tracker | One click sends the module to your Daily Tracker as today’s target |
Pace: one module ≈ 2–4 study days with the study loop. Don’t binge two modules in a day — recall needs sleep between exposures.
The Modules
| # | Module | You’ll be able to |
|---|---|---|
| 01 | How Java Actually Runs | Install the JDK, run code without an IDE, read a stack trace |
| 02 | The Language Core | Variables, strings, arrays, loops, methods — write real small programs |
| 03 | OOP As A Design Tool | Design with classes, choose composition over inheritance, use interfaces |
| 04 | Collections | Pick the right List/Set/Map and explain HashMap internals |
| 05 | Generics | Read and write type-safe code, understand <T> in library signatures |
| 06 | Exceptions | Design errors, read deep stack traces, never swallow a failure |
| 07 | Lambdas And Streams | Transform data pipelines — and know when a plain loop is better |
| 08 | Concurrency Foundations | Explain race conditions, fix them, run tasks with ExecutorService |
| 09 | Memory And GC | Watch the heap live, explain GC, find a memory leak |
| 10 | Capstone — SplitEase CLI | Build a complete expense-splitter using modules 01–09 |
The Rule For This Track
Type everything yourself. Every snippet, every exercise. Reading Java is not knowing Java — your fingers learn the language before your brain does.
When you finish module 10, you are ready for the Spring Boot track — and SplitEase becomes the project you’ll rebuild as a real API.