Stop Re-requesting Tokens

Imagine you’re boarding a bus every morning. Instead of buying a monthly pass, you run back to the counter for a new ticket every single ride.

That’s exactly what happens when your app keeps re-requesting tokens. It doesn’t need to.

External APIs often require short-lived tokens.

If you are gonna re-request tokens every time, your app gets slow, verbose, and sometimes blocked.

This Story explains a battle-tested pattern that keeps tokens valid in memory, refreshes them only when needed.

The Big Idea

• Keep one in-memory token instance.
• Before using the token, check if it’s expired.
• refresh If expires— but only once, even if multiple threads are looking into it.

If you’ve worked with REST APIs that use OAuth2 client credentials, and to understand You just need some Java basics — and to know what a token looks like.

Read it here if you are blocked by paywall.

We will have 4 classes.

1. APIConfig — configure client_id / secret, paths, and give a RestClient bean.
2. APITokenConnector — makes the actual call to get a token.
3. TokenHandler — keeps the token in memory, refreshes…