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← Theory library
Enterprise Java theory
JVM internals, Spring Boot 3, Reactive Streams, and Web3j.
Practise in the Code Lab →Easy
- 1. Java Virtual Machine (JVM)Understanding the execution environment for Java.
- 2. JRE vs JDKDistinguishing between runtime and development kits.
- 3. Bytecode BasicsThe intermediate representation of Java code.
- 4. Object-Oriented PrinciplesFour pillars of Java OOP.
- 5. Access ModifiersControlling visibility of members.
- 6. Java PackagesOrganizing Java classes.
- 7. Primitive Data TypesBasic building blocks of data.
- 8. Wrapper ClassesObject versions of primitives.
- 9. Garbage Collection IntroAutomatic memory management.
- 10. Exception Handling (Try-Catch)Dealing with errors gracefully.
- 11. Checked vs Unchecked ExceptionsCompile-time vs Runtime errors.
- 12. Java Collections: ListOrdered sequences of elements.
- 13. Java Collections: SetUnique collections.
- 14. Java Collections: MapKey-value pairs.
- 15. Maven LifecycleStandardizing the build process.
- 16. Gradle BasicsFlexible build automation.
- 17. Spring IoC ContainerThe heart of Spring framework.
- 18. Dependency Injection (DI)Pattern for decoupling.
- 19. JDBC BasicsConnecting to relational databases.
- 20. Main MethodEntry point of a program.
Medium
- 21. JVM Memory Model (Heap vs Stack)How memory is structured.
- 22. Garbage Collection: G1 CollectorModern garbage collection.
- 23. ClassLoadersHow classes are loaded.
- 24. Thread LifecycleStates of a thread.
- 25. Synchronized KeywordMutual exclusion.
- 26. Thread Pools (ExecutorService)Managing worker threads.
- 27. Spring Bean ScopesVisibility and lifecycle of beans.
- 28. Spring Boot AutoconfigurationOpinionated setup.
- 29. Spring MVC FlowWeb request handling.
- 30. JPA vs JDBCORM vs Direct SQL.
- 31. Web3j: SetupJava library for Ethereum.
- 32. Web3j: Smart Contract WrappersType-safe contract interaction.
- 33. Reactive Streams (Project Reactor)Non-blocking programming.
- 34. Java Modules (Jigsaw)Modularizing the JDK.
- 35. Java Generic WildcardsFlexible type parameters.
- 36. Java Reflection APIInspecting code at runtime.
- 37. Java 8 Streams: Intermediate OpsTransforming data pipelines.
Hard
- 38. JVM Profiling (JFR & JMC)Monitoring performance.
- 39. Memory Leaks in JavaWhen GC cannot help.
- 40. Fork/Join FrameworkParallel processing for recursive tasks.
- 41. ZGC (Zero Garbage Collector)Ultra-low pause collector.
- 42. Web3j: Transaction SigningSecuring on-chain actions.
- 43. Spring Security ArchitectureProtecting the enterprise.
- 44. Spring AOP InternalsAspect Oriented Programming.
- 45. RLP EncodingEthereum's serialization format.
- 46. Custom Maven PluginsExtending build logic.
- 47. Bytecode Manipulation (ASM)Modifying code at runtime.
- 48. Distributed Transactions in SpringManaging multiple resources.
- 49. EIP-1559 and Gas in JavaDynamic fee markets.
- 50. Java Native Interface (JNI)Calling C/C++ from Java.