Full coverage of Java concurrency: platform threads, virtual threads (Java 21), Runnable vs Callable, ExecutorService, Future, atomic classes, synchronized, ReentrantLock, volatile, concurrent collections, deadlock, and parallel streams — with real-world thread-safety traps.
Complete guide to Java control flow: if/else, switch statements and expressions, while/do-while/for loops, break/continue with labels, and pattern matching — including Java 21 switch with when guards.
Master Java's core APIs: String, StringBuilder, arrays, Arrays utility class, Math API, BigInteger/BigDecimal, and the modern Date-Time API including daylight saving time shifts.
Covers interfaces (default, static, private methods), functional interfaces, enums with fields/constructors, records, sealed classes, and nested classes — all featuring heavily in the OCP Java 21 exam with Java 21-specific additions like pattern matching and exhaustive switch.
Comprehensive OCP Java SE 21 (1Z0-830) exam cheat-sheet: output tracing strategy, compile vs runtime errors, Java 21 new features, mnemonics, top traps across all 14 chapters, functional interface cheatsheet, stream operations, collections comparison, and a final checklist.
Practical guide to modern Java features introduced from Java 8 through Java 21, with emphasis on high-impact language updates.
A structured Docusaurus study guide covering all 14 chapters of the OCP Oracle Certified Professional Java SE 21 Developer exam (1Z0-830), with beginner explanations, senior deep-dives, exam tips, and Spring framework context.