Oracle Java guides for Java SE 17, Java SE 21, and Java 25-aligned study paths.
This section groups Oracle Java developer exam guides. These pages are code-reading first: compile-time legality, type inference, object model rules, collections, streams, modules, concurrency, I/O, localization, and modern Java feature boundaries.
| Exam | Focus | Best first page |
|---|---|---|
| 1Z0-829 | Java SE 17 Developer code-reading and API contract decisions. | Cheat Sheet |
| 1Z0-830 | Java SE 21 Developer Professional code-reading, modern Java features, and sample questions. | Sample Questions |
| 1Z0-831 | Java 25-aligned professional study path; confirm exact scheduling facts on Oracle before booking. | Cheat Sheet |
For Java exams, do not start by predicting output. First decide whether the code compiles, then resolve the declared types, overloads, generic bounds, exception rules, and API contracts.