JakartaEE China Community, official website: jakarta.ee/zh/community/china; gitee.com/jakarta-ee-china; space.bilibili.com/518946941; reply "Join group" to get QR code
This tutorial shows how to use JBang scripts to launch a WildFly server, create a simple Jakarta REST endpoint, and extend the server with WildFly Glow add‑ons such as Kafka, providing step‑by‑step commands, code examples, and Docker integration for rapid prototyping.
This article explains the different cache layers—client, application, database, and distributed—provides best‑practice guidelines, and shows how to configure client‑side headers, application‑side caches with Hazelcast, JPA second‑level caching, and JMS‑based cache coordination in GlassFish.
This guide walks through the importance of Retrieval‑Augmented Generation, outlines the core Langchain4j and Ollama 3 components, and provides a complete Java example—including Maven setup, document ingestion, embedding creation, similarity search, prompt construction, and response generation—to demonstrate a functional RAG pipeline.
Generational ZGC, introduced in JDK 21, applies a weak generational hypothesis to split the heap into young and old regions, improving throughput by ~10%, reducing max pause times by 10‑20%, mitigating allocation stalls, and offering a phased adoption path via JVM flags and diagnostic tools.
This guide walks you through setting up a Jakarta EE project, configuring Maven and WildFly, adding security constraints and login settings in web.xml, defining users and roles, and testing basic authentication with curl to protect a simple RESTful endpoint.
This tutorial walks you through setting up the JDK, Maven, and a Jakarta EE‑compatible server, generating a project with the Eclipse Starter, writing a simple REST endpoint, configuring the WildFly Maven plugin, and testing the service via a browser or curl, all with concrete code examples.
This article explains why Retrieval‑Augmented Generation improves LLM accuracy, outlines the key Langchain4j and Ollama3 components, and provides a step‑by‑step Java example—including Maven setup, document ingestion, embedding, similarity search, prompt creation, and response generation—to demonstrate a functional RAG pipeline.
Logs, tracing, and metrics each serve distinct monitoring goals—logs capture discrete events for debugging and audit, traces map request flows to pinpoint performance bottlenecks, and metrics provide time‑series health data; understanding their differences and integrating tools like ELK, OpenTelemetry, Prometheus, and Grafana enables robust observability.
The article examines JDK 21's Generational ZGC, explaining its weak generational hypothesis, heap partitioning, performance gains such as a 10% throughput increase and reduced pause times, mitigation of allocation stalls, migration steps, and diagnostic tools for developers.
The article explains why ConcurrentModificationException occurs when a Java collection is structurally modified during iteration, illustrates typical scenarios such as enhanced‑for loops and multithreaded access, and provides practical solutions including iterator.remove(), thread‑safe collections, synchronized blocks and iterating over copies.
