👀 Views: 0 💬 Answers: 1 📅 Created: 2025-09-21

spring-boot oauth-2.0 rest-api Java

I'm following best practices but I've searched everywhere and can't find a clear answer. While integrating a third-party API into my local development environment, I've hit a snag with OAuth 2.0 token refreshing. I'm using Spring Boot (version 2.5.4) along with the Spring Security OAuth library. The initial access token works fine for making requests, but when it expires, the refresh token doesn't seem to be recognized, leading to a `401 Unauthorized` response. To give you some context, I've set up the OAuth flow correctly and am storing the tokens in memory as follows: ```java public class AuthService { private String accessToken; private String refreshToken; public void storeTokens(String access, String refresh) { this.accessToken = access; this.refreshToken = refresh; } } ``` On token expiry, I attempt to refresh it like this: ```java public String refreshAccessToken() { String url = "https://api.example.com/oauth/token"; HttpHeaders headers = new HttpHeaders(); headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED); MultiValueMap<String, String> body = new LinkedMultiValueMap<>(); body.add("grant_type", "refresh_token"); body.add("refresh_token", refreshToken); HttpEntity<MultiValueMap<String, String>> requestEntity = new HttpEntity<>(body, headers); ResponseEntity<String> response = restTemplate.postForEntity(url, requestEntity, String.class); if (response.getStatusCode() == HttpStatus.OK) { // Handle token response } else { throw new RuntimeException("Failed to refresh token"); } } ``` Despite following OAuth best practices, I consistently receive a `400 Bad Request` response, indicating that the request might be malformed. I've double-checked the request body and the authorization headers, and they seem correct. The library documentation doesn't provide indication of required parameters beyond what I've included. One approach I considered is logging the full request and response. I added a logger to capture the HTTP interactions, which revealed that the refresh token is indeed being sent. However, the third-party service returns errors without providing detailed insights into what might be missing or incorrect. Could there be an issue with how I'm formatting the refresh request? Or is it possible that the local environment is interfering with the OAuth flow? Any insights on how to debug this or alternative strategies for managing token refresh would be greatly appreciated. I'm developing on Windows 10 with Java.