Have you had experience integrating OAuth 2.0 protocol into your projects?

Yes, I have experience integrating OAuth 2.0 into Java projects. I usually used this protocol for user authorization through third-party services (e.g., Google, Facebook). During integration, I implemented obtaining the authorization code, exchanging it for an access token, and also token renewal. To simplify, I often used libraries such as Spring Security OAuth, which provide ready-made mechanisms for working with OAuth 2.0.

An example of simplified code using Spring Security to configure an OAuth 2.0 client:

@Configuration
@EnableOAuth2Client
public class OAuth2ClientConfig {

    @Bean
    public OAuth2RestTemplate oauth2RestTemplate(OAuth2ClientContext clientContext) {
        return new OAuth2RestTemplate(resource(), clientContext);
    }

    @Bean
    public OAuth2ProtectedResourceDetails resource() {
        AuthorizationCodeResourceDetails details = new AuthorizationCodeResourceDetails();
        details.setClientId("client-id");
        details.setClientSecret("client-secret");
        details.setAccessTokenUri("https://provider.com/oauth/token");
        details.setUserAuthorizationUri("https://provider.com/oauth/authorize");
        details.setScope(Arrays.asList("read", "write"));
        return details;
    }
}

This approach allows for secure and standardized integration of authorization via OAuth 2.0.