How to Implement Server-Sent Events (SSE) in Spring Boot - SseEmitter / WebFlux Implementation Guide
A guide to implementing Server-Sent Events (SSE) in Spring Boot. Covers implementations using Spring MVC's SseEmitter and WebFlux's Flux<ServerSentEvent>, automatic reconnection with EventSource and resumption via Last-Event-ID, broadcasting to multiple clients, production pitfalls such as Nginx's proxy_buffering, and a practical example of relaying LLM streaming responses.