Java 25 1Z0-831 30-, 60-, and 90-day study plan with topic order, review loops, and final-week priorities.
Use this study plan when you want a disciplined route through Java 25 plus Oracle Professional Java reasoning instead of jumping between random language features. The exam-style habit is still the same: compile first, contract second, output last.
| If your background is… | Better route |
|---|---|
you already passed 1Z0-829 or 1Z0-830 and mainly need the Java 25 delta |
2-3 weeks |
| you are comfortable with modern Java but not Oracle exam style | 4-6 weeks |
| you have solid Java basics but weaker streams, generics, or concurrency reasoning | 6-8 weeks |
| you are not yet reliable at compile-vs-runtime triage | slow down and use the 8+ week route |
| Week | Focus | What to do |
|---|---|---|
| 1 | types and flow | work 1. Core and 2. Flow until you stop guessing on legality |
| 2 | classes and hierarchies | work 3. Constructors and 4. Inheritance |
| 3 | collections and generics | work 5. Collections and re-drill mutability and bounds daily |
| 4 | streams and gatherers | work 6. Streams plus repeat collector-vs-gatherer contrasts |
| 5 | concurrency and modules | work 7. Concurrency and 8. Modules |
| 6 | I/O, exceptions, and mixed review | finish 9. I/O and 10. Exceptions, then use the cheat sheet daily |
Spend extra attention on:
compile, runtime, API contract, preview status, or mutability/order| Day | Focus |
|---|---|
| 1 | compile-time legality, var, conversions, pattern/switch rules |
| 2 | classes, records, flexible constructors, sealed hierarchies |
| 3 | collections, generics, wildcards, mutability |
| 4 | streams, collectors, gatherers, encounter order |
| 5 | virtual threads, scoped values, structured concurrency, preview rules |
| 6 | modules, launch model, files, localization, exceptions |
| 7 | mixed snippets only; no new topics |