What problem does it solve? Java applications often produce unstructured text logs that are hard to parse, filter, and analyze, especially when debugging request flows or feeding logs to AI assistants. This Skill provides proven patterns for structured JSON logging, request tracing with correlation IDs, and profile-based log format switching. ## Core Features & Use Cases - Structured JSON Logging: Configure Spring Boot 3.4+ native structured logging (logstash, ecs, gelf formats) or Logstash Logback Encoder for older versions. - Request Tracing with MDC: Add requestId, traceId, and custom fields to every log entry so you can follow a single request through the entire application flow. - AI-Friendly Log Formats: Emit logs that AI tools like Claude Code can parse directly with jq queries, reducing token usage and interpretation errors. - Use Case: You need to debug why an order failed in production. With JSON logs and requestId tracing, you run cat app.log | jq 'select(.requestId == "req-abc123")' and instantly see every step, duration, and error for that request. ## Quick Start Ask the AI to set up structured JSON logging with request tracing in your Spring Boot application using the logging patterns skill.