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Latest from Java Companion

88 recent articles

Java Companion

Nov 11, 2025 · Backend Development

Mastering Spring Boot Logging: Levels, Persistence, Formatting, and Lombok Simplification

This article explains why traditional System.out printing is insufficient, introduces Spring Boot's built‑in SLF4J/Logback logging, demonstrates how to obtain and use a logger, details log levels, configuration of log levels, file persistence, rolling policies, formatting, and shows how Lombok's @Slf4j annotation can simplify logger usage.

ConfigurationSpringBootlogback

0 likes · 17 min read

Mastering Spring Boot Logging: Levels, Persistence, Formatting, and Lombok Simplification

Java Companion

Nov 9, 2025 · Databases

Why Big Companies Avoid SET for User Data: A Redis Storage Guide

The article compares storing user objects in Redis using plain SET with JSON versus using HASH fields, providing code demos, benchmark results, memory and concurrency analysis, and practical guidelines on when to choose each approach for optimal performance and safety.

Data ModelingHashJava

0 likes · 9 min read

Why Big Companies Avoid SET for User Data: A Redis Storage Guide

Java Companion

Nov 8, 2025 · Backend Development

How Jackson Views Let One DTO Replace Many and End DTO Explosion

The article explains how Jackson Views can consolidate multiple DTO classes into a single DTO by using view interfaces and @JsonView annotations, dramatically reducing code duplication, simplifying maintenance, and providing flexible field selection for different API scenarios.

JavaSpringdto

0 likes · 11 min read

How Jackson Views Let One DTO Replace Many and End DTO Explosion

Java Companion

Nov 4, 2025 · Backend Development

Boosting Dubbo Performance with Spring Boot Auto‑Configuration and a Multi‑Data‑Source SDK

The article details how a high‑frequency Dubbo call bottleneck was resolved by creating a conditional Spring Boot auto‑configuration multi‑data‑source SDK that dynamically loads beans, avoids bean conflicts, and enables direct database access, dramatically reducing latency and system load.

Conditional BeanDubboMulti-DataSource

0 likes · 12 min read

Boosting Dubbo Performance with Spring Boot Auto‑Configuration and a Multi‑Data‑Source SDK

Java Companion

Nov 2, 2025 · Operations

A Complete Jenkins + Maven + Git Automation Deployment Guide

This article walks through setting up three servers (GitLab, Jenkins, and a test machine), creating a GitLab project and token, configuring Maven and Jenkins plugins, defining Git, branch, and Maven settings, and implementing pre‑ and post‑steps—including a cleanup script and SSH publishing—to automatically build and deploy a Spring Boot JAR, while addressing common pitfalls such as missing manifest attributes and port conflicts.

AutomationCI/CDGit

0 likes · 10 min read

A Complete Jenkins + Maven + Git Automation Deployment Guide

Java Companion

Oct 31, 2025 · Backend Development

How to Stream Local Video with Spring Boot, FFmpeg, and ZLMediaKit

This guide walks through setting up ZLMediaKit in Docker, installing FFmpeg, adding a Spring Boot backend with configuration and service classes to launch and manage RTMP streams, and provides front‑end HTML/JavaScript for playing the live FLV or HLS streams.

FLVJavaRTMP

0 likes · 15 min read

How to Stream Local Video with Spring Boot, FFmpeg, and ZLMediaKit

Java Companion

Oct 30, 2025 · Backend Development

Spring Boot Hot Patch Loader: Quick Fix for Critical Production Bugs

This article explains how to build a Spring Boot hot‑patch loader that uses Java agents and dynamic class loading to apply runtime patches—such as Spring Bean, plain class, or static method replacements—allowing urgent bug fixes in production within minutes without restarting the service.

Dynamic Loadinghot-patchjava-agent

0 likes · 34 min read

Spring Boot Hot Patch Loader: Quick Fix for Critical Production Bugs

Java Companion

Oct 28, 2025 · Backend Development

Java 25 Released: New Features Make the Language More Concise, Efficient, and Modern

Java 25, the latest LTS release, introduces pattern matching for primitive types, module‑wide imports, a compact main method, enhanced records, structured concurrency, scoped and stable values, a vector API, compact object headers, generational Shenandoah GC, AOT optimizations, JFR improvements, security updates, and drops 32‑bit support, offering developers a more concise, safer, and higher‑performance platform.

JDK 25JEPJava

0 likes · 10 min read

Java 25 Released: New Features Make the Language More Concise, Efficient, and Modern