Secure Admin Login with React + Spring Boot 🔐 | Fix CORS & Basic Auth! The trial and error method!

In this video, we build a secure admin login system using React (frontend) and Spring Boot (backend). You'll learn how to:

✅Research solutions for strange problems and solve them
✅ Set up Basic Authentication with Spring Security
✅ Create a protected /admin endpoint in your controller
✅ Authenticate from the React frontend using fetch
✅ Fix the dreaded CORS error: “No 'Access-Control-Allow-Origin' header...”
✅ Allow selective route protection (/admin/** secure, /api/articles/** public)
✅ Use proper Spring Security CORS config (without deprecated .and()!)

This is perfect if you're building a blog or CMS with admin features, and want to secure backend endpoints while allowing public access to regular articles.

📌 Tools used:

React with React Router

Spring Boot 3.x

Spring Security 6

In-Memory UserDetails

CORS Configuration in Java

curl + Postman for testing

💡 Tip: If your React login fails but curl works — it’s probably CORS. We show you exactly how to fix that.

🛡️ Time to lock down your app like a pro.