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Deep, tested guides for Java & the JVM — and the computer-science fundamentals underneath.
From Spring Boot and Hibernate migration playbooks to JUnit testing, 8086 assembly, and AI in Java, ankurm.com is a reference-grade library of tutorials written from real debugging experience — not rephrased docs.
“Every great developer was once a beginner who didn’t quit.”
Java & the JVM
The core of the site — production-tested guides across the Spring and Hibernate ecosystem.
Java118Language features, collections, concurrency & modern Java.
Spring21Spring Boot, configuration, web & data essentials.
Spring Cloud18Gateway, Eureka, Resilience4j & microservice migrations.
Hibernate / JPA51Mappings, fetching, performance & version migrations.
JUnit67JUnit 5 & 6 testing patterns, basics to advanced.
Jackson10JSON serialization, custom (de)serializers & tuning.
AI, Prompts & Patterns
Modern tooling and timeless design sense applied to Java work.
Assembly, Web & More
The breadth that makes this a one-stop study and reference hub.
8086 Assembly48TASM/MASM programs & the complete instruction set.
Operating Systems14Scheduling, synchronization & OS algorithm programs.
TypeScript11Types, generics & practical front-end typing.
Angular7Components, services & app-building walkthroughs.
Code Snippets196Quick, copy-ready solutions to everyday problems.
All Posts→The full chronological archive of everything published.
Computer-Science Fundamentals
Curated program collections for core CS & engineering courses.
Featured Migration Playbooks
The site’s most in-depth, frequently-referenced upgrade guides.
HibernateHibernate 5 → 6 → 7: the breaking changes and the silent ones
Spring SecuritySpring Security 5 → 6 → 7: SecurityFilterChain & silent authorization changes
SpringRestTemplate → RestClient: method mapping, error handling & the exchange() trap
Spring CloudZuul → Spring Cloud Gateway: routes, filters & blocking-call traps
Latest From the Blog
The 10 most recent posts, updated automatically as new content goes live.
- Singleton Design Pattern in Java: The Definitive Guide (All Implementations + Pitfalls)The Singleton pattern guarantees exactly one instance of a class — but Java’s threading model, serialization, and reflection make it harder than it looks. Complete guide: all 6 implementations (Eager, Lazy, synchronized, DCL, Holder, Enum), thread-safety analysis, Spring singletons, pitfalls, and when NOT to use it.
- Prototype Design Pattern in Java: Complete Guide with ExamplesThe Prototype pattern lets you clone objects without depending on their concrete classes. Complete Java guide: Cloneable pitfalls, deep vs shallow copy, copy constructors, serialization-based cloning, JDK usage, and when to use each approach.
- Builder Design Pattern in Java: Complete Guide with ExamplesThe Builder pattern separates complex object construction from its representation, eliminating telescoping constructors and invalid partial state. Complete Java guide with runnable examples, Lombok @Builder, JDK usage (StringBuilder, Stream.Builder), pitfalls, and FAQs.
- Abstract Factory Design Pattern in Java: Complete Guide with ExamplesThe Abstract Factory pattern lets you create families of related objects without specifying their concrete classes. Complete Java guide with runnable cross-platform UI example, JDK usage, comparison with Factory Method, pitfalls, and FAQs.
- Factory Method Design Pattern in Java: Complete Guide with ExamplesThe Factory Method pattern lets subclasses decide which object to create, eliminating if/else creation logic and making your codebase open for extension without modification. Complete guide with runnable Java examples, JDK usage, Spring Boot integration, pitfalls, and FAQs.
- Spring Security 5 to 6 to 7 Migration: SecurityFilterChain, Lambda DSL, and the Silent Authorization ChangesOf every breaking change in the Spring Boot 2 → 3 era, the removal of WebSecurityConfigurerAdapter generated the most confused stack traces I’ve debugged — because security configuration … Continue reading Spring Security 5 to 6 to 7 Migration: SecurityFilterChain, Lambda DSL, and the Silent Authorization Changes
- RestTemplate to RestClient Migration Guide: Method Mapping, Error Handling, and the exchange() TrapSpring Boot 4 finally forced the issue: RestTemplate, in maintenance mode since Spring 5, is out of the recommended path, and codebases full of getForObject() and exchange() calls … Continue reading RestTemplate to RestClient Migration Guide: Method Mapping, Error Handling, and the exchange() Trap
- Hibernate 5 to 6 to 7 Migration Guide: The Breaking Changes and the Silent OnesI have now taken three codebases through the Hibernate 5 → 6 → 7 path, and the same pattern repeated each time: the compile errors are the easy … Continue reading Hibernate 5 to 6 to 7 Migration Guide: The Breaking Changes and the Silent Ones
- Zuul to Spring Cloud Gateway Migration: Routes, Filters, and the Blocking-Call TrapsThe first time I ported a Zuul gateway to Spring Cloud Gateway, the routes took an afternoon — and the filters took two weeks. That ratio surprises every … Continue reading Zuul to Spring Cloud Gateway Migration: Routes, Filters, and the Blocking-Call Traps
- Spring Cloud Netflix to Modern Alternatives: The Complete Migration Guide (2026)In 2020 I published a dozen tutorials on this site covering Eureka, Hystrix, Zuul, Ribbon, and Feign — the Spring Cloud Netflix stack. They were accurate then. Today, … Continue reading Spring Cloud Netflix to Modern Alternatives: The Complete Migration Guide (2026)