--- title: "#java articles | Hashnode" description: "Java is a general-purpose computer-programming language that is concurrent, class-based, object-oriented, and specifically designed to have as few implementa..." url: "https://hashnode.com/tag/java" --- Tag # #java 13,866 posts · 130,565 followers [Scholar Logic](https://hashnode.com/@scholarlogic) · [3h ago](https://hashnode.com/posts/a-beginner-java-project-should-explain-its-failure-cases/6af45de627b575f00bee2d6d) ### [A Beginner Java Project Should Explain Its Failure Cases](https://scholarlogic.hashnode.dev/a-beginner-java-project-should-explain-its-failure-cases?utm_source=hashnode&utm_medium=feed) Plan a Java library checkout exercise with clear rules, synthetic data, failure tests and an honest README. 2 min read · [scholarlogic.hashnode.dev](https://scholarlogic.hashnode.dev/a-beginner-java-project-should-explain-its-failure-cases?utm_source=hashnode&utm_medium=feed) [Shai Almog](https://hashnode.com/@codenameone) · [15h ago](https://hashnode.com/posts/grapheneos-lineageos-e-os-and-others-are-now-officially-supported/6af3be502faf7c27e1415380) ### [GrapheneOS, LineageOS, /e/OS and Others Are Now Officially Supported](https://debugagent.com/grapheneos-lineageos-e-os-and-others-are-now-officially-supported?utm_source=hashnode&utm_medium=feed) Codename One now officially supports GrapheneOS, LineageOS, CalyxOS, /e/OS and other Android builds without Google, with a boundary CI verifies and push through UnifiedPush. Also: the Android compatibility layer now runs Room, WorkManager, location… 6 min read · [debugagent.com](https://debugagent.com/grapheneos-lineageos-e-os-and-others-are-now-officially-supported?utm_source=hashnode&utm_medium=feed) [Andrii Zhukovskyi](https://hashnode.com/@zhukovskyi) · [1d ago](https://hashnode.com/posts/why-a-java-pod-gets-oomkilled-in-kubernetes-with-a-half-empty-heap/6af3351518573de2479b867a) ### [Why a Java pod gets OOMKilled in Kubernetes with a half-empty heap](https://zhukovskyi.hashnode.dev/why-a-java-pod-gets-oomkilled-in-kubernetes-with-a-half-empty-heap?utm_source=hashnode&utm_medium=feed) In short. A container memory limit covers everything the JVM uses, and the heap is only part of it. Metaspace, thread stacks, the code cache and direct buffers live outside the heap, so a pod with -Xm 6 min read · [zhukovskyi.hashnode.dev](https://zhukovskyi.hashnode.dev/why-a-java-pod-gets-oomkilled-in-kubernetes-with-a-half-empty-heap?utm_source=hashnode&utm_medium=feed) [Shai Almog](https://hashnode.com/@codenameone) · [1d ago](https://hashnode.com/posts/reel-your-own-streaming-service-or-course-platform/6af26cd2ed09eb0ad382c7ae) ### [Reel: Your Own Streaming Service or Course Platform](https://debugagent.com/reel-your-own-streaming-service-or-course-platform?utm_source=hashnode&utm_medium=feed) Reel is a streaming service and its server in one Java project. Flip a preset and it's a subscription service, a creator platform with community uploads, or an academy with courses and quizzes. Codename One also gained a streaming API with DRM… 6 min read · [debugagent.com](https://debugagent.com/reel-your-own-streaming-service-or-course-platform?utm_source=hashnode&utm_medium=feed) [Siddhesh Sawant](https://hashnode.com/@siddheshsawant) · [1d ago](https://hashnode.com/posts/what-transactional-actually-does-proxies-thread-bound-connections-and-the-rules-of-rollback/6af337d134a4ea32f9e0e3e8) ### [What @Transactional Actually Does: Proxies, Thread-Bound Connections and the Rules of Rollback](https://siddheshsawant.hashnode.dev/what-transactional-actually-does-proxies-thread-bound-connections-and-the-rules-of-rollback?utm_source=hashnode&utm_medium=feed) One annotation, and Spring opens a database transaction, shares its connection with every repository you call, and decides whether to commit or roll back. This article traces a single @Transactional call through the proxy, TransactionInterceptor and the transaction manager, then uses that model to explain propagation, isolation, rollback rules and the pitfalls that follow from them. 33 min read · [siddheshsawant.hashnode.dev](https://siddheshsawant.hashnode.dev/what-transactional-actually-does-proxies-thread-bound-connections-and-the-rules-of-rollback?utm_source=hashnode&utm_medium=feed) [Milan Nikic](https://hashnode.com/@nick79) · [1d ago](https://hashnode.com/posts/cross-site-scripting-xss-in-java-and-react-reflected-and-stored-xss-part-1/6af30aeb5f0f17eb1bf10a48) ### [Cross-Site Scripting (XSS) in Java and React: Reflected and Stored XSS (Part 1)](https://securitydepth.hashnode.dev/cross-site-scripting-xss-in-java-and-react-reflected-and-stored-xss-part-1?utm_source=hashnode&utm_medium=feed) Prevent reflected and stored XSS in Java and React with practical examples of output encoding, safe rendering, and HTML sanitization. 20 min read · [securitydepth.hashnode.dev](https://securitydepth.hashnode.dev/cross-site-scripting-xss-in-java-and-react-reflected-and-stored-xss-part-1?utm_source=hashnode&utm_medium=feed) [Marco Pedroza](https://hashnode.com/@mpedroza) · [1d ago](https://hashnode.com/posts/building-a-high-performance-event-driven-rate-limiter-with-openresty-valkey-redis-prometheus/6af24665fb748db1724d6abf) ### [Building a High-Performance Event-Driven Rate Limiter with OpenResty, Valkey(Redis) & Prometheus](https://mpedroza.hashnode.dev/building-a-high-performance-event-driven-rate-limiter-with-openresty-valkey-redis-prometheus?utm_source=hashnode&utm_medium=feed) A Practical Guide to protect your spring boot applications from a large number of concurrent requests. 13 min read · [mpedroza.hashnode.dev](https://mpedroza.hashnode.dev/building-a-high-performance-event-driven-rate-limiter-with-openresty-valkey-redis-prometheus?utm_source=hashnode&utm_medium=feed) [1](https://hashnode.com/posts/building-a-high-performance-event-driven-rate-limiter-with-openresty-valkey-redis-prometheus/6af24665fb748db1724d6abf) [Sahil Maddi](https://hashnode.com/@CollaborativeCoder4U) · [1d ago](https://hashnode.com/posts/the-four-pillars-of-oop-in-java-a-quick-overview/6af2846b067848452be4d7d2) ### [The Four Pillars of OOP in Java: A Quick Overview 🧱](https://oops-concepts.hashnode.dev/the-four-pillars-of-oop-in-java-a-quick-overview?utm_source=hashnode&utm_medium=feed) Object-Oriented Programming (OOP) is the backbone of Java. Every class you write, every Spring bean you inject and every library you use is built on four ideas: encapsulation, inheritance, polymorphis 5 min read · [oops-concepts.hashnode.dev](https://oops-concepts.hashnode.dev/the-four-pillars-of-oop-in-java-a-quick-overview?utm_source=hashnode&utm_medium=feed) [Sahil Maddi](https://hashnode.com/@CollaborativeCoder4U) · [1d ago](https://hashnode.com/posts/monolith-vs-microservices-a-quick-overview-for-java-developers/6af2842819a44e81e5c58e1e) ### [Monolith vs Microservices: A Quick Overview for Java Developers 🧩](https://collaborativecoder4u.hashnode.dev/monolith-vs-microservices-a-quick-overview-for-java-developers?utm_source=hashnode&utm_medium=feed) "Should we build microservices?" is one of the most common architecture questions in Java teams today. Microservices power some of the world's largest systems, but a well-structured monolith is still 4 min read · [collaborativecoder4u.hashnode.dev](https://collaborativecoder4u.hashnode.dev/monolith-vs-microservices-a-quick-overview-for-java-developers?utm_source=hashnode&utm_medium=feed) [Gowtham Muthuvel](https://hashnode.com/@GowthamMuthuvel) · [1d ago](https://hashnode.com/posts/spring-security-jwt-refresh-token-rotation-rbac/6af29fea91696569429d27db) ### [JWT + Role-Based Access in Spring Security: Refresh Tokens Without the Footguns](https://gowthammuthuvel.hashnode.dev/spring-security-jwt-refresh-token-rotation-rbac?utm_source=hashnode&utm_medium=feed) Rotation with reuse detection, ROLE\_ vs SCOPE\_ mapping, and the permitAll() trap, all tested on Spring Boot 4.1.2. Replaying an old refresh token revoked 2 tokens and killed the session. 20 min read · [gowthammuthuvel.hashnode.dev](https://gowthammuthuvel.hashnode.dev/spring-security-jwt-refresh-token-rotation-rbac?utm_source=hashnode&utm_medium=feed)