Building a Full Enterprise-Ready React + Spring Boot Auth Flow: An End-to-End Guide

Introduction Authentication is one of those things that looks simple in a tutorial and becomes surprisingly complex in production. Between token storage, CSRF protection, refresh flows, and protected routing, there are many places to get it wrong—and getting it wrong has real security consequences. In two earlier posts, I covered pieces of this puzzle: Enabling CSRF in a JWT-Based React + Spring Boot Application and Storing Personal Information in React: sessionStorage vs Context API . This post ties those threads together into a complete, end-to-end authentication flow you can adapt for enterprise applications. We'll walk through the full journey: login → token issuance → secure storage → protected routes → token refresh → logout. Architecture Overview Before the code, here's the high-level flow: ┌──────────────┐ ┌──────────────────┐ │ React │ │ Spring Boot │ │ Frontend │ │ Backend │ └──────┬───────┘ └────────┬─────────┘ │ 1. POST /login │ │─────────────────────────>│ │ │ validate credentials │ 2. JWT (httpOnly cookie)│ issue access + refresh │<─────────────────────────│ │ │ │ 3. GET /protected │ │ (+ CSRF token) │ │─────────────────────────>│ validate JWT + CSRF │ 4. Protected data │ │<─────────────────────────│ │ │ │ 5. POST /refresh │ │─────────────────────────>│ rotate tokens │ │ │ 6. POST /logout │ │─────────────────────────>│ invalidate session Key Design Decisions Decision Choice Rationale Token storage httpOnly cookies Not accessible to JavaScript → mitigates XSS token theft CSRF protection Double-submit / token pattern Required when using cookies Token type Short-lived access + refresh Limits exposure window State management Context API for auth status Centralized, lightweight Why httpOnly cookies over localStorage? As I discussed in the storage blog, localStorage is readable by any script on the page—making it vulnerable to XSS. httpOnly cookies trade that risk for the need to handle CSRF, which we address below. Step 1: Backend — Login and Token Issuance