Refactor. Add docs. Fix dependencies.

spring-cloud-openfeign-core/src/main/java/org/springframework/cloud/openfeign/FeignAutoConfiguration.java

@@ -51,7 +51,6 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
-import org.springframework.boot.autoconfigure.security.oauth2.client.OAuth2ClientProperties;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.cache.interceptor.CacheInterceptor;
 import org.springframework.cloud.client.actuator.HasFeatures;
@@ -383,13 +382,11 @@ public class FeignAutoConfiguration {
 		@Bean
 		@ConditionalOnBean({OAuth2AuthorizedClientService.class, ClientRegistrationRepository.class})
 		public OAuth2AccessTokenInterceptor defaultOAuth2AccessTokenInterceptor(
-			@Value("${spring.cloud.openfeign.oauth2.specifiedClientIds:}") List<String> specifiedClientIds,
-			OAuth2ClientProperties oAuth2ClientProperties,
+			@Value("${spring.cloud.openfeign.oauth2.clientId:}") String clientId,
 			OAuth2AuthorizedClientService oAuth2AuthorizedClientService,
 			ClientRegistrationRepository clientRegistrationRepository) {
-
-			return new OAuth2AccessTokenInterceptor(specifiedClientIds, oAuth2ClientProperties,
-				oAuth2AuthorizedClientService, clientRegistrationRepository);
+			return new OAuth2AccessTokenInterceptor(clientId, oAuth2AuthorizedClientService,
+				clientRegistrationRepository);
 		}
 
 	}

spring-cloud-openfeign-core/src/main/java/org/springframework/cloud/openfeign/security/OAuth2AccessTokenInterceptor.java

@@ -16,17 +16,14 @@
 
 package org.springframework.cloud.openfeign.security;
 
+import java.net.URI;
 import java.time.Instant;
-import java.util.ArrayList;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
 import java.util.Optional;
 
 import feign.RequestInterceptor;
 import feign.RequestTemplate;
+import feign.Target;
 
-import org.springframework.boot.autoconfigure.security.oauth2.client.OAuth2ClientProperties;
 import org.springframework.security.authentication.AnonymousAuthenticationToken;
 import org.springframework.security.core.Authentication;
 import org.springframework.security.core.authority.AuthorityUtils;
@@ -38,16 +35,22 @@ import org.springframework.security.oauth2.client.OAuth2AuthorizedClientManager;
 import org.springframework.security.oauth2.client.OAuth2AuthorizedClientService;
 import org.springframework.security.oauth2.client.registration.ClientRegistrationRepository;
 import org.springframework.security.oauth2.core.OAuth2AccessToken;
+import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
 /**
- * RequestInterceptor for OAuth2 Feign Requests. By default, It uses the
+ * A {@link RequestInterceptor} for OAuth2 Feign Requests. By default, it uses the
  * {@link AuthorizedClientServiceOAuth2AuthorizedClientManager } to get
- * {@link OAuth2AuthorizedClient } that hold an {@link OAuth2AccessToken }. Use the
- * Client(s) from properties if not specific the field
- * {@link OAuth2AccessTokenInterceptor#specifiedClientIds}
+ * {@link OAuth2AuthorizedClient } that holds an {@link OAuth2AccessToken }. If the user
+ * has specified an OAuth2 {@code clientId} using the
+ * {@code spring.cloud.openfeign.oauth2.clientId} property, it will be used to retrieve
+ * the token. If the token is not retrieved or the {@code clientId} has not been
+ * specified, the {@code serviceId} retrieved from the {@code url} host segment will be
+ * used. This approach is convenient for load-balanced Feign clients. For
+ * non-load-balanced ones, the property-based {@code clientId} is a suitable approach.
  *
  * @author Dangzhicairang(小水牛)
+ * @author Olga Maciaszek-Sharma
  * @since 4.0.0
  */
 public class OAuth2AccessTokenInterceptor implements RequestInterceptor {
@@ -66,9 +69,7 @@ public class OAuth2AccessTokenInterceptor implements RequestInterceptor {
 
 	private final String header;
 
-	private final List<String> specifiedClientIds;
-
-	private final OAuth2ClientProperties oAuth2ClientProperties;
+	private final String clientId;
 
 	private final OAuth2AuthorizedClientService oAuth2AuthorizedClientService;
 
@@ -79,69 +80,56 @@ public class OAuth2AccessTokenInterceptor implements RequestInterceptor {
 	}
 
 	private static final Authentication ANONYMOUS_AUTHENTICATION = new AnonymousAuthenticationToken("anonymous",
-		"anonymousUser", AuthorityUtils.createAuthorityList("ROLE_ANONYMOUS"));
+			"anonymousUser", AuthorityUtils.createAuthorityList("ROLE_ANONYMOUS"));
 
-	public OAuth2AccessTokenInterceptor(OAuth2ClientProperties oAuth2ClientProperties,
-		OAuth2AuthorizedClientService oAuth2AuthorizedClientService,
-		ClientRegistrationRepository clientRegistrationRepository) {
-		this(new ArrayList<>(), oAuth2ClientProperties, oAuth2AuthorizedClientService, clientRegistrationRepository);
+	public OAuth2AccessTokenInterceptor(OAuth2AuthorizedClientService oAuth2AuthorizedClientService,
+			ClientRegistrationRepository clientRegistrationRepository) {
+		this(null, oAuth2AuthorizedClientService, clientRegistrationRepository);
 	}
 
-	public OAuth2AccessTokenInterceptor(List<String> specifiedClientIds, OAuth2ClientProperties oAuth2ClientProperties,
-		OAuth2AuthorizedClientService oAuth2AuthorizedClientService,
-		ClientRegistrationRepository clientRegistrationRepository) {
-		this(BEARER, AUTHORIZATION, specifiedClientIds, oAuth2ClientProperties, oAuth2AuthorizedClientService,
-			clientRegistrationRepository);
+	public OAuth2AccessTokenInterceptor(String clientId, OAuth2AuthorizedClientService oAuth2AuthorizedClientService,
+			ClientRegistrationRepository clientRegistrationRepository) {
+		this(BEARER, AUTHORIZATION, clientId, oAuth2AuthorizedClientService, clientRegistrationRepository);
 	}
 
-	public OAuth2AccessTokenInterceptor(String tokenType, String header, List<String> specifiedClientIds,
-		OAuth2ClientProperties oAuth2ClientProperties, OAuth2AuthorizedClientService oAuth2AuthorizedClientService,
-		ClientRegistrationRepository clientRegistrationRepository) {
+	public OAuth2AccessTokenInterceptor(String tokenType, String header, String clientId,
+			OAuth2AuthorizedClientService oAuth2AuthorizedClientService,
+			ClientRegistrationRepository clientRegistrationRepository) {
 		this.tokenType = tokenType;
 		this.header = header;
-		this.specifiedClientIds = specifiedClientIds;
-		this.oAuth2ClientProperties = oAuth2ClientProperties;
+		this.clientId = clientId;
 		this.oAuth2AuthorizedClientService = oAuth2AuthorizedClientService;
 		this.authorizedClientManager = new AuthorizedClientServiceOAuth2AuthorizedClientManager(
-			clientRegistrationRepository, this.oAuth2AuthorizedClientService);
+				clientRegistrationRepository, this.oAuth2AuthorizedClientService);
 	}
 
 	@Override
 	public void apply(RequestTemplate template) {
+		OAuth2AccessToken token = getToken(template);
+		String extractedToken = String.format("%s %s", tokenType, token.getTokenValue());
 		template.header(header);
-		template.header(header, extract(tokenType));
+		template.header(header, extractedToken);
 	}
 
-	protected String extract(String tokenType) {
-		OAuth2AccessToken accessToken = getToken();
-		return String.format("%s %s", tokenType, accessToken.getTokenValue());
-	}
-
-	public OAuth2AccessToken getToken() {
-
-		// if specific, try to use them to get token.
-		for (String clientId : this.specifiedClientIds) {
-			OAuth2AccessToken token = this.getToken(clientId);
+	public OAuth2AccessToken getToken(RequestTemplate template) {
+		// If specified, try to use them to get token.
+		if (StringUtils.hasText(clientId)) {
+			OAuth2AccessToken token = getToken(clientId);
 			if (token != null) {
 				return token;
 			}
 		}
 
-		// use clients from properties by default
-		for (String clientId : Optional.ofNullable(this.oAuth2ClientProperties)
-			.map(OAuth2ClientProperties::getRegistration).map(Map::keySet)
-			.orElse(new HashSet<>())) {
-			OAuth2AccessToken token = this.getToken(clientId);
-			if (token != null) {
-				return token;
-			}
+		// If not specified use host (synonymous with serviceId for load-balanced
+		// requests; non-load-balanced requests should use the method above).
+		OAuth2AccessToken token = getToken(getServiceId(template));
+		if (token != null) {
+			return token;
 		}
-
-		throw new IllegalStateException("No token acquired, which is illegal according to the contract.");
+		throw new IllegalStateException("OAuth2 token has not been successfully acquired.");
 	}
 
 	protected OAuth2AccessToken getToken(String clientId) {
-
 		if (!StringUtils.hasText(clientId)) {
 			return null;
 		}
@@ -151,27 +139,35 @@ public class OAuth2AccessTokenInterceptor implements RequestInterceptor {
 			principal = ANONYMOUS_AUTHENTICATION;
 		}
 
-		// already exist
+		// Already exist
 		OAuth2AuthorizedClient oAuth2AuthorizedClient = oAuth2AuthorizedClientService.loadAuthorizedClient(clientId,
-			principal.getName());
+				principal.getName());
 		if (oAuth2AuthorizedClient != null) {
 			OAuth2AccessToken accessToken = oAuth2AuthorizedClient.getAccessToken();
-			if (accessToken != null && this.noExpire(accessToken)) {
+			if (accessToken != null && notExpired(accessToken)) {
 				return accessToken;
 			}
 		}
 
 		OAuth2AuthorizeRequest authorizeRequest = OAuth2AuthorizeRequest.withClientRegistrationId(clientId)
-			.principal(principal).build();
-		OAuth2AuthorizedClient authorize = this.authorizedClientManager.authorize(authorizeRequest);
-		return Optional.ofNullable(authorize).map(OAuth2AuthorizedClient::getAccessToken)
-			.filter(this::noExpire)
-			.orElse(null);
+				.principal(principal).build();
+		OAuth2AuthorizedClient authorizedClient = authorizedClientManager.authorize(authorizeRequest);
+		return Optional.ofNullable(authorizedClient).map(OAuth2AuthorizedClient::getAccessToken)
+				.filter(this::notExpired).orElse(null);
 	}
 
-	protected boolean noExpire(OAuth2AccessToken token) {
+	protected boolean notExpired(OAuth2AccessToken token) {
 		return Optional.ofNullable(token).map(OAuth2AccessToken::getExpiresAt)
-			.map(expire -> expire.isAfter(Instant.now())).orElse(false);
+				.map(expire -> expire.isAfter(Instant.now())).orElse(false);
+	}
+
+	private static String getServiceId(RequestTemplate template) {
+		Target<?> feignTarget = template.feignTarget();
+		Assert.notNull(feignTarget, "feignTarget may not be null");
+		String url = feignTarget.url();
+		Assert.hasLength(url, "url may not be empty");
+		final URI originalUri = URI.create(url);
+		return originalUri.getHost();
 	}
 
 }

spring-cloud-openfeign-core/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -79,6 +79,12 @@
 			"type": "java.lang.Boolean",
 			"description": "Enables load balancing for oauth2 access token provider.",
 			"defaultValue": "false"
+		},
+		{
+			"name": "feign.oauth2.registrationClientId",
+			"type": "java.lang.String",
+			"description": "Provides a clientId to be used with OAuth2.",
+			"defaultValue": ""
 		}
 	]
 }

spring-cloud-openfeign-core/src/test/java/org/springframework/cloud/openfeign/FeignAutoConfigurationTests.java

@@ -17,8 +17,6 @@
 package org.springframework.cloud.openfeign;
 
 import java.lang.reflect.Method;
-import java.util.ArrayList;
-import java.util.List;
 
 import feign.Target;
 import org.assertj.core.api.Condition;
@@ -141,17 +139,12 @@ class FeignAutoConfigurationTests {
 	@Test
 	void shouldInstantiateFeignOAuth2FeignRequestInterceptor() {
 		runner.withPropertyValues("spring.cloud.openfeign.oauth2.enabled=true",
-				"spring.cloud.openfeign.oauth2.specifiedClientIds=feign-client")
+				"spring.cloud.openfeign.oauth2.clientId=feign-client")
 			.withBean(OAuth2AuthorizedClientService.class, () -> mock(OAuth2AuthorizedClientService.class))
 			.withBean(ClientRegistrationRepository.class, () -> mock(ClientRegistrationRepository.class))
 			.run(ctx -> {
 				assertOauth2AccessTokenInterceptorExists(ctx);
-				assertThatOauth2AccessTokenInterceptorHasSpecifiedIdsPropertyWithValue(ctx,
-					new ArrayList<String>() {
-						{
-							add("feign-client");
-						}
-					});
+				assertThatOauth2AccessTokenInterceptorHasSpecifiedIdsPropertyWithValue(ctx, "feign-client");
 			});
 	}
 
@@ -184,9 +177,9 @@ class FeignAutoConfigurationTests {
 	}
 
 	private void assertThatOauth2AccessTokenInterceptorHasSpecifiedIdsPropertyWithValue(
-		ConfigurableApplicationContext ctx, List<String> expectedValue) {
+		ConfigurableApplicationContext ctx, String expectedValue) {
 		final OAuth2AccessTokenInterceptor bean = ctx.getBean(OAuth2AccessTokenInterceptor.class);
-		assertThat(bean).hasFieldOrPropertyWithValue("specifiedClientIds", expectedValue);
+		assertThat(bean).hasFieldOrPropertyWithValue("clientId", expectedValue);
 	}
 
 	private void assertOnlyOneTargeterPresent(ConfigurableApplicationContext ctx, Class<?> beanClass) {

spring-cloud-openfeign-core/src/test/java/org/springframework/cloud/openfeign/security/OAuth2AccessTokenInterceptorTests.java

@@ -17,15 +17,14 @@
 package org.springframework.cloud.openfeign.security;
 
 import java.time.Instant;
-import java.util.HashMap;
 
 import feign.Request.HttpMethod;
 import feign.RequestTemplate;
-import org.assertj.core.api.Assertions;
+import feign.Target;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
-import org.springframework.boot.autoconfigure.security.oauth2.client.OAuth2ClientProperties;
+import org.springframework.security.oauth2.client.OAuth2AuthorizeRequest;
 import org.springframework.security.oauth2.client.OAuth2AuthorizedClient;
 import org.springframework.security.oauth2.client.OAuth2AuthorizedClientManager;
 import org.springframework.security.oauth2.client.OAuth2AuthorizedClientService;
@@ -35,121 +34,117 @@ import org.springframework.security.oauth2.core.AuthorizationGrantType;
 import org.springframework.security.oauth2.core.OAuth2AccessToken;
 import org.springframework.util.AlternativeJdkIdGenerator;
 
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyString;
-import static org.mockito.BDDMockito.given;
+import static org.mockito.ArgumentMatchers.argThat;
+import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
 
 /**
+ * Tests for {@link OAuth2AccessTokenInterceptor}.
+ *
  * @author Dangzhicairang(小水牛)
+ * @author Olga Maciaszek-Sharma
+ *
  */
 class OAuth2AccessTokenInterceptorTests {
 
+	private final OAuth2AuthorizedClientService mockOAuth2AuthorizedClientService = mock(
+			OAuth2AuthorizedClientService.class);
+
+	private final OAuth2AuthorizedClientManager mockOAuth2AuthorizedClientManager = mock(
+			OAuth2AuthorizedClientManager.class);
+
 	private OAuth2AccessTokenInterceptor oAuth2AccessTokenInterceptor;
 
 	private RequestTemplate requestTemplate;
 
-	private OAuth2ClientProperties mockOAuth2ClientProperties;
-
 	private static final String DEFAULT_CLIENT_ID = "feign-client";
 
 	@BeforeEach
 	void setUp() {
-
 		requestTemplate = new RequestTemplate().method(HttpMethod.GET);
-
-		mockOAuth2ClientProperties = mock(OAuth2ClientProperties.class);
-		given(mockOAuth2ClientProperties.getRegistration())
-			.willReturn(new HashMap<String, OAuth2ClientProperties.Registration>() {
-				{
-					put(DEFAULT_CLIENT_ID, mock(OAuth2ClientProperties.Registration.class));
-				}
-			});
-
+		Target<?> feignTarget = mock(Target.class);
+		when(feignTarget.url()).thenReturn("http://test");
+		requestTemplate.feignTarget(feignTarget);
 	}
 
 	@Test
-	void noTokenAcquired() {
-
-		OAuth2AuthorizedClientService mockOAuth2AuthorizedClientService = mock(OAuth2AuthorizedClientService.class);
-		given(mockOAuth2AuthorizedClientService.loadAuthorizedClient(anyString(), anyString())).willReturn(null);
-
-		oAuth2AccessTokenInterceptor = new OAuth2AccessTokenInterceptor(mockOAuth2ClientProperties,
-			mockOAuth2AuthorizedClientService, mock(ClientRegistrationRepository.class));
-
-		OAuth2AuthorizedClientManager mockOAuth2AuthorizedClientManager = mock(OAuth2AuthorizedClientManager.class);
-		given(mockOAuth2AuthorizedClientManager.authorize(any())).willReturn(null);
-
+	void shouldThrowExceptionWhenNoTokenAcquired() {
+		when(mockOAuth2AuthorizedClientService.loadAuthorizedClient(anyString(), anyString())).thenReturn(null);
+		oAuth2AccessTokenInterceptor = new OAuth2AccessTokenInterceptor(mockOAuth2AuthorizedClientService,
+				mock(ClientRegistrationRepository.class));
+		when(mockOAuth2AuthorizedClientManager.authorize(any())).thenReturn(null);
 		oAuth2AccessTokenInterceptor.setAuthorizedClientManager(mockOAuth2AuthorizedClientManager);
 
-		Assertions.assertThatExceptionOfType(IllegalStateException.class)
-			.isThrownBy(() -> oAuth2AccessTokenInterceptor.apply(requestTemplate))
-			.withMessage("No token acquired, which is illegal according to the contract.");
-
+		assertThatExceptionOfType(IllegalStateException.class)
+				.isThrownBy(() -> oAuth2AccessTokenInterceptor.apply(requestTemplate))
+				.withMessage("OAuth2 token has not been successfully acquired.");
 	}
 
 	@Test
-	void validTokenAcquired() {
-
-		OAuth2AuthorizedClientService mockOAuth2AuthorizedClientService = mock(OAuth2AuthorizedClientService.class);
-		given(mockOAuth2AuthorizedClientService.loadAuthorizedClient(anyString(), anyString())).willReturn(null);
-
-		oAuth2AccessTokenInterceptor = new OAuth2AccessTokenInterceptor(mockOAuth2ClientProperties,
-			mockOAuth2AuthorizedClientService, mock(ClientRegistrationRepository.class));
-
-		OAuth2AuthorizedClientManager mockOAuth2AuthorizedClientManager = mock(OAuth2AuthorizedClientManager.class);
-		given(mockOAuth2AuthorizedClientManager.authorize(any())).willReturn(validTokenOAuth2AuthorizedClient());
-
+	void shouldAcquireValidToken() {
+		when(mockOAuth2AuthorizedClientService.loadAuthorizedClient(anyString(), anyString())).thenReturn(null);
+		oAuth2AccessTokenInterceptor = new OAuth2AccessTokenInterceptor(mockOAuth2AuthorizedClientService,
+				mock(ClientRegistrationRepository.class));
+		when(mockOAuth2AuthorizedClientManager.authorize(
+				argThat((OAuth2AuthorizeRequest request) -> ("test").equals(request.getClientRegistrationId()))))
+						.thenReturn(validTokenOAuth2AuthorizedClient());
 		oAuth2AccessTokenInterceptor.setAuthorizedClientManager(mockOAuth2AuthorizedClientManager);
 
 		oAuth2AccessTokenInterceptor.apply(requestTemplate);
 
-		Assertions.assertThat(requestTemplate.headers().get("Authorization"))
-			.contains("Bearer Valid Token");
+		assertThat(requestTemplate.headers().get("Authorization")).contains("Bearer Valid Token");
 	}
 
 	@Test
-	void expireTokenAcquired() {
-
-		OAuth2AuthorizedClientService mockOAuth2AuthorizedClientService = mock(OAuth2AuthorizedClientService.class);
-		given(mockOAuth2AuthorizedClientService.loadAuthorizedClient(anyString(), anyString())).willReturn(null);
-
-		oAuth2AccessTokenInterceptor = new OAuth2AccessTokenInterceptor(mockOAuth2ClientProperties,
-			mockOAuth2AuthorizedClientService, mock(ClientRegistrationRepository.class));
-
-		OAuth2AuthorizedClientManager mockOAuth2AuthorizedClientManager = mock(OAuth2AuthorizedClientManager.class);
-		given(mockOAuth2AuthorizedClientManager.authorize(any())).willReturn(expiredTokenOAuth2AuthorizedClient());
-
+	void shouldThrowExceptionWhenExpiredTokenAcquired() {
+		when(mockOAuth2AuthorizedClientService.loadAuthorizedClient(anyString(), anyString())).thenReturn(null);
+		oAuth2AccessTokenInterceptor = new OAuth2AccessTokenInterceptor(mockOAuth2AuthorizedClientService,
+				mock(ClientRegistrationRepository.class));
+		when(mockOAuth2AuthorizedClientManager.authorize(any())).thenReturn(expiredTokenOAuth2AuthorizedClient());
 		oAuth2AccessTokenInterceptor.setAuthorizedClientManager(mockOAuth2AuthorizedClientManager);
 
-		Assertions.assertThatExceptionOfType(IllegalStateException.class)
-			.isThrownBy(() -> oAuth2AccessTokenInterceptor.apply(requestTemplate))
-			.withMessage("No token acquired, which is illegal according to the contract.");
+		assertThatExceptionOfType(IllegalStateException.class)
+				.isThrownBy(() -> oAuth2AccessTokenInterceptor.apply(requestTemplate))
+				.withMessage("OAuth2 token has not been successfully acquired.");
 	}
 
 	@Test
-	void acquireTokenFromAuthorizedClient() {
-		OAuth2AuthorizedClientService mockOAuth2AuthorizedClientService = mock(OAuth2AuthorizedClientService.class);
-		given(mockOAuth2AuthorizedClientService.loadAuthorizedClient(anyString(), anyString()))
-			.willReturn(validTokenOAuth2AuthorizedClient());
-
-		oAuth2AccessTokenInterceptor = new OAuth2AccessTokenInterceptor(mockOAuth2ClientProperties,
-			mockOAuth2AuthorizedClientService, mock(ClientRegistrationRepository.class));
+	void shouldAcquireTokenFromAuthorizedClient() {
+		when(mockOAuth2AuthorizedClientService.loadAuthorizedClient(eq("test"), anyString()))
+				.thenReturn(validTokenOAuth2AuthorizedClient());
+		oAuth2AccessTokenInterceptor = new OAuth2AccessTokenInterceptor(mockOAuth2AuthorizedClientService,
+				mock(ClientRegistrationRepository.class));
 
 		oAuth2AccessTokenInterceptor.apply(requestTemplate);
 
-		Assertions.assertThat(requestTemplate.headers().get("Authorization"))
-			.contains("Bearer Valid Token");
+		assertThat(requestTemplate.headers().get("Authorization")).contains("Bearer Valid Token");
+	}
+
+	@Test
+	void shouldAcquireValidTokenFromSpecifiedClientId() {
+		when(mockOAuth2AuthorizedClientService.loadAuthorizedClient(eq("testId"), anyString()))
+				.thenReturn(validTokenOAuth2AuthorizedClient());
+		oAuth2AccessTokenInterceptor = new OAuth2AccessTokenInterceptor("testId", mockOAuth2AuthorizedClientService,
+				mock(ClientRegistrationRepository.class));
+
+		oAuth2AccessTokenInterceptor.apply(requestTemplate);
+
+		assertThat(requestTemplate.headers().get("Authorization")).contains("Bearer Valid Token");
 	}
 
 	private OAuth2AccessToken validToken() {
 		return new OAuth2AccessToken(OAuth2AccessToken.TokenType.BEARER, "Valid Token", Instant.now(),
-			Instant.now().plusSeconds(60L));
+				Instant.now().plusSeconds(60L));
 	}
 
 	private OAuth2AccessToken expiredToken() {
 		return new OAuth2AccessToken(OAuth2AccessToken.TokenType.BEARER, "Expired Token",
-			Instant.now().minusSeconds(61L), Instant.now().minusSeconds(60L));
+				Instant.now().minusSeconds(61L), Instant.now().minusSeconds(60L));
 	}
 
 	private OAuth2AuthorizedClient validTokenOAuth2AuthorizedClient() {
@@ -161,10 +156,9 @@ class OAuth2AccessTokenInterceptorTests {
 	}
 
 	private ClientRegistration defaultClientRegistration() {
-		return ClientRegistration.withRegistrationId(new AlternativeJdkIdGenerator().generateId()
-				.toString())
-			.clientId(DEFAULT_CLIENT_ID).tokenUri("mock token uri")
-			.authorizationGrantType(AuthorizationGrantType.CLIENT_CREDENTIALS).build();
+		return ClientRegistration.withRegistrationId(new AlternativeJdkIdGenerator().generateId().toString())
+				.clientId(DEFAULT_CLIENT_ID).tokenUri("mock token uri")
+				.authorizationGrantType(AuthorizationGrantType.CLIENT_CREDENTIALS).build();
 	}
 
 }