How to Implement the OAuth 2.0 Authorization Code Flow in Java
Visual Overview: sequenceDiagram participant User participant App as Client App participant AuthServer as Authorization Server participant Resource as Resource Server User->>App: 1. Click Login App->>AuthServer: 2. Authorization Request AuthServer->>User: 3. Login Page User->>AuthServer: 4. Authenticate AuthServer->>App: 5. Authorization Code App->>AuthServer: 6. Exchange Code for Token AuthServer->>App: 7. Access Token + Refresh Token App->>Resource: 8. API Request with Token Resource->>App: 9. Protected Resource OAuth 2.0’s Authorization Code Flow is the go-to standard for securing web applications that need to interact with identity providers on behalf of users. In this guide, we’ll walk through how to implement this flow in Java using industry-standard libraries — and explain each step along the way. ...