#983 - Switch to Spring's ServerWebExchangeContextFilter.

Replace HypermediaWebFilter with ServerWebExchangeContextFilter.

Related issues: spring-projects/spring-framework#21746

Author: gregturn

src/main/java/org/springframework/hateoas/config/WebFluxHateoasConfiguration.java

@@ -27,13 +27,13 @@
 import org.springframework.context.annotation.Lazy;
 import org.springframework.core.codec.CharSequenceEncoder;
 import org.springframework.core.codec.StringDecoder;
-import org.springframework.hateoas.server.reactive.HypermediaWebFilter;
 import org.springframework.http.codec.CodecConfigurer;
 import org.springframework.http.codec.ServerCodecConfigurer;
 import org.springframework.http.codec.json.Jackson2JsonDecoder;
 import org.springframework.http.codec.json.Jackson2JsonEncoder;
 import org.springframework.lang.NonNull;
 import org.springframework.util.MimeType;
+import org.springframework.web.filter.reactive.ServerWebExchangeContextFilter;
 import org.springframework.web.reactive.config.WebFluxConfigurer;
 import org.springframework.web.reactive.function.client.WebClient;
 
@@ -67,14 +67,10 @@ HypermediaWebFluxConfigurer hypermediaWebFluxConfigurer(ObjectProvider<ObjectMap
 		return new HypermediaWebFluxConfigurer(mapper.getIfAvailable(ObjectMapper::new), hypermediaTypes);
 	}
 
-	/**
-	 * TODO: Replace with Spring Framework filter when https://github.com/spring-projects/spring-framework/issues/21746 is
-	 * completed.
-	 */
 	@Bean
-	@Lazy // To avoid creation on a WebMVC app using WebClient only
-	HypermediaWebFilter hypermediaWebFilter() {
-		return new HypermediaWebFilter();
+	@Lazy
+	ServerWebExchangeContextFilter serverWebExchangeContextFilter() {
+		return new ServerWebExchangeContextFilter();
 	}
 
 	/**

src/main/java/org/springframework/hateoas/server/reactive/HypermediaWebFilter.java

@@ -15,7 +15,7 @@
  */
 package org.springframework.hateoas.server.reactive;
 
-import static org.springframework.hateoas.server.reactive.HypermediaWebFilter.*;
+import static org.springframework.web.filter.reactive.ServerWebExchangeContextFilter.*;
 
 import lombok.RequiredArgsConstructor;
 
@@ -241,7 +241,7 @@ private static UriComponentsBuilder getBuilder(@Nullable ServerWebExchange excha
 	private static Mono<WebFluxLinkBuilder> linkToInternal(Object invocation) {
 
 		return linkToInternal(invocation,
-				Mono.subscriberContext().map(context -> getBuilder(context.getOrDefault(SERVER_WEB_EXCHANGE, null))));
+				Mono.subscriberContext().map(context -> getBuilder(context.getOrDefault(EXCHANGE_CONTEXT_ATTRIBUTE, null))));
 	}
 
 	private static Mono<WebFluxLinkBuilder> linkToInternal(Object invocation, Mono<UriComponentsBuilder> exchange) {

src/main/java/org/springframework/hateoas/server/reactive/WebFluxLinkBuilder.java

@@ -40,6 +40,8 @@
 import org.springframework.web.reactive.config.EnableWebFlux;
 
 /**
+ * Verify WebFlux properly activates the {@link org.springframework.web.filter.reactive.ServerWebExchangeContextFilter}.
+ *
  * @author Greg Turnquist
  */
 class HypermediaWebFilterTest {

src/test/java/org/springframework/hateoas/server/reactive/HypermediaWebFilterTest.java

@@ -17,8 +17,8 @@
 
 import static org.assertj.core.api.Assertions.*;
 import static org.mockito.Mockito.*;
-import static org.springframework.hateoas.server.reactive.HypermediaWebFilter.*;
 import static org.springframework.hateoas.server.reactive.WebFluxLinkBuilder.*;
+import static org.springframework.web.filter.reactive.ServerWebExchangeContextFilter.*;
 
 import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
@@ -82,7 +82,7 @@ void linkAtSameLevelAsContextProvidedServerExchangeShouldWork() {
 		when(this.request.getHeaders()).thenReturn(new HttpHeaders());
 
 		linkTo(methodOn(TestController.class).root()).withSelfRel().toMono() //
-				.subscriberContext(Context.of(SERVER_WEB_EXCHANGE, this.exchange)) //
+				.subscriberContext(Context.of(EXCHANGE_CONTEXT_ATTRIBUTE, this.exchange)) //
 				.as(StepVerifier::create).expectNextMatches(link -> {
 
 					assertThat(link.getRel()).isEqualTo(IanaLinkRelations.SELF);
@@ -126,7 +126,7 @@ void shallowLinkFromDeepContextProvidedServerExchangeShouldWork() {
 		when(this.request.getHeaders()).thenReturn(new HttpHeaders());
 
 		linkTo(methodOn(TestController.class).root()).withSelfRel().toMono() //
-				.subscriberContext(Context.of(SERVER_WEB_EXCHANGE, this.exchange)) //
+				.subscriberContext(Context.of(EXCHANGE_CONTEXT_ATTRIBUTE, this.exchange)) //
 				.as(StepVerifier::create).expectNextMatches(link -> {
 
 					assertThat(link.getRel()).isEqualTo(IanaLinkRelations.SELF);
@@ -169,7 +169,7 @@ void deepLinkFromShallowContextProvidedServerExchangeShouldWork() {
 		when(this.request.getHeaders()).thenReturn(new HttpHeaders());
 
 		linkTo(methodOn(TestController.class).deep()).withSelfRel().toMono() //
-				.subscriberContext(Context.of(SERVER_WEB_EXCHANGE, this.exchange)) //
+				.subscriberContext(Context.of(EXCHANGE_CONTEXT_ATTRIBUTE, this.exchange)) //
 				.as(StepVerifier::create).expectNextMatches(link -> {
 
 					assertThat(link.getRel()).isEqualTo(IanaLinkRelations.SELF);
@@ -191,7 +191,7 @@ void linkToRouteWithNoMappingShouldWork() {
 		when(this.request.getHeaders()).thenReturn(new HttpHeaders());
 
 		linkTo(methodOn(TestController2.class).root()).withSelfRel().toMono() //
-				.subscriberContext(Context.of(SERVER_WEB_EXCHANGE, this.exchange)) //
+				.subscriberContext(Context.of(EXCHANGE_CONTEXT_ATTRIBUTE, this.exchange)) //
 				.as(StepVerifier::create).expectNextMatches(link -> {
 
 					assertThat(link.getRel()).isEqualTo(IanaLinkRelations.SELF);