BearerFixOAuth2ClientContext.java

package config;

import org.springframework.security.oauth2.client.DefaultOAuth2ClientContext;
import org.springframework.security.oauth2.common.DefaultOAuth2AccessToken;
import org.springframework.security.oauth2.common.OAuth2AccessToken;

class BearerFixOAuth2ClientContext extends DefaultOAuth2ClientContext {
    @Override
    public void setAccessToken(OAuth2AccessToken accessToken) {
        if ("bearer".equals(accessToken.getTokenType())) {
            final DefaultOAuth2AccessToken fixedToken = new DefaultOAuth2AccessToken(accessToken);
            fixedToken.setTokenType("Bearer");
            super.setAccessToken(fixedToken);
        } else {
            super.setAccessToken(accessToken);
        }
    }
}

BitBucketClientConfig.java

package config;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.web.client.RestTemplateBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.oauth2.client.OAuth2ClientContext;
import org.springframework.security.oauth2.client.OAuth2RestTemplate;
import org.springframework.security.oauth2.client.resource.OAuth2ProtectedResourceDetails;
import org.springframework.security.oauth2.client.token.grant.client.ClientCredentialsResourceDetails;
import org.springframework.security.oauth2.common.AuthenticationScheme;

@Configuration
public class BitBucketClientConfig {
    private final BitBucketProperties bitBucketProperties;

    @Autowired
    public BitBucketClientConfig(BitBucketProperties bitBucketProperties) {
        this.bitBucketProperties = bitBucketProperties;
    }

    @Bean
    public OAuth2ProtectedResourceDetails bitbucketDetails() {
        final ClientCredentialsResourceDetails resourceDetails =
                new ClientCredentialsResourceDetails();

        resourceDetails.setId("bitbucket");
        resourceDetails.setAccessTokenUri(bitBucketProperties.getAccessTokenUri());
        resourceDetails.setClientId(bitBucketProperties.getConsumerKey());
        resourceDetails.setClientSecret(bitBucketProperties.getConsumerSecret());
        resourceDetails.setAuthenticationScheme(AuthenticationScheme.header);

        return resourceDetails;
    }

    @Bean
    public OAuth2ClientContext bitbucketContext() {
        return new BearerFixOAuth2ClientContext();
    }

    @Bean
    public OAuth2RestTemplate bitBucketRestTemplate(RestTemplateBuilder restTemplateBuilder) {
        final OAuth2RestTemplate restTemplate = new OAuth2RestTemplate(bitbucketDetails(), bitbucketContext());

        return restTemplateBuilder
                .rootUri(bitBucketProperties.getBaseUrl())
                .configure(restTemplate);
    }
}