Merge branch '5.3.x' into main

build.gradle

@@ -65,7 +65,7 @@ configure(allprojects) { project ->
 			}
 
 			dependency "io.reactivex.rxjava3:rxjava:3.1.1"
-			dependency "io.smallrye.reactive:mutiny:1.0.0"
+			dependency "io.smallrye.reactive:mutiny:1.1.1"
 			dependency "io.projectreactor.tools:blockhound:1.0.6.RELEASE"
 
 			dependency "com.fasterxml:aalto-xml:1.3.0"

spring-webflux/src/main/java/org/springframework/web/reactive/resource/ResourceWebHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -96,7 +96,9 @@ public class ResourceWebHandler implements WebHandler, InitializingBean {
 
 	private final List<String> locationValues = new ArrayList<>(4);
 
-	private final List<Resource> locations = new ArrayList<>(4);
+	private final List<Resource> locationResources = new ArrayList<>(4);
+
+	private final List<Resource> locationsToUse = new ArrayList<>(4);
 
 	private final List<ResourceResolver> resourceResolvers = new ArrayList<>(4);
 
@@ -147,9 +149,9 @@ public class ResourceWebHandler implements WebHandler, InitializingBean {
 	 * for serving static resources.
 	 */
 	public void setLocations(@Nullable List<Resource> locations) {
-		this.locations.clear();
+		this.locationResources.clear();
 		if (locations != null) {
-			this.locations.addAll(locations);
+			this.locationResources.addAll(locations);
 		}
 	}
 
@@ -159,11 +161,18 @@ public class ResourceWebHandler implements WebHandler, InitializingBean {
 	 * <p>Note that if {@link #setLocationValues(List) locationValues} are provided,
 	 * instead of loaded Resource-based locations, this method will return
 	 * empty until after initialization via {@link #afterPropertiesSet()}.
+	 * <p><strong>Note:</strong> As of 5.3.11 the list of locations is filtered
+	 * to exclude those that don't actually exist and therefore the list returned
+	 * from this method may be a subset of all given locations.
 	 * @see #setLocationValues
 	 * @see #setLocations
 	 */
 	public List<Resource> getLocations() {
-		return this.locations;
+		if (this.locationsToUse.isEmpty()) {
+			// Possibly not yet initialized, return only what we have so far
+			return this.locationResources;
+		}
+		return this.locationsToUse;
 	}
 
 	/**
@@ -295,7 +304,7 @@ public class ResourceWebHandler implements WebHandler, InitializingBean {
 	public void afterPropertiesSet() throws Exception {
 		resolveResourceLocations();
 
-		if (logger.isWarnEnabled() && CollectionUtils.isEmpty(this.locations)) {
+		if (logger.isWarnEnabled() && CollectionUtils.isEmpty(getLocations())) {
 			logger.warn("Locations list is empty. No resources will be served unless a " +
 					"custom ResourceResolver is configured as an alternative to PathResourceResolver.");
 		}
@@ -316,21 +325,22 @@ public class ResourceWebHandler implements WebHandler, InitializingBean {
 	}
 
 	private void resolveResourceLocations() {
-		if (CollectionUtils.isEmpty(this.locationValues)) {
-			return;
-		}
-		else if (!CollectionUtils.isEmpty(this.locations)) {
-			throw new IllegalArgumentException("Please set either Resource-based \"locations\" or " +
-					"String-based \"locationValues\", but not both.");
+		List<Resource> result = new ArrayList<>(this.locationResources);
+
+		if (!this.locationValues.isEmpty()) {
+			Assert.notNull(this.resourceLoader,
+					"ResourceLoader is required when \"locationValues\" are configured.");
+			Assert.isTrue(CollectionUtils.isEmpty(this.locationResources), "Please set " +
+					"either Resource-based \"locations\" or String-based \"locationValues\", but not both.");
+			for (String location : this.locationValues) {
+				result.add(this.resourceLoader.getResource(location));
+			}
 		}
 
-		Assert.notNull(this.resourceLoader,
-				"ResourceLoader is required when \"locationValues\" are configured.");
+		result = result.stream().filter(Resource::exists).collect(Collectors.toList());
 
-		for (String location : this.locationValues) {
-			Resource resource = this.resourceLoader.getResource(location);
-			this.locations.add(resource);
-		}
+		this.locationsToUse.clear();
+		this.locationsToUse.addAll(result);
 	}
 
 	/**
@@ -339,7 +349,7 @@ public class ResourceWebHandler implements WebHandler, InitializingBean {
 	 * match the {@link #setLocations locations} configured on this class.
 	 */
 	protected void initAllowedLocations() {
-		if (CollectionUtils.isEmpty(this.locations)) {
+		if (CollectionUtils.isEmpty(getLocations())) {
 			if (logger.isInfoEnabled()) {
 				logger.info("Locations list is empty. No resources will be served unless a " +
 						"custom ResourceResolver is configured as an alternative to PathResourceResolver.");
@@ -618,8 +628,8 @@ public class ResourceWebHandler implements WebHandler, InitializingBean {
 		if (!this.locationValues.isEmpty()) {
 			return this.locationValues.stream().collect(Collectors.joining("\", \"", "[\"", "\"]"));
 		}
-		else if (!this.locations.isEmpty()) {
-			return "[" + this.locations.toString()
+		if (!getLocations().isEmpty()) {
+			return "[" + getLocations().toString()
 					.replaceAll("class path resource", "Classpath")
 					.replaceAll("ServletContext resource", "ServletContext") + "]";
 		}

spring-webflux/src/main/java/org/springframework/web/reactive/result/method/annotation/AbstractMessageWriterResultHandler.java

@@ -52,7 +52,7 @@ import org.springframework.web.server.ServerWebExchange;
  */
 public abstract class AbstractMessageWriterResultHandler extends HandlerResultHandlerSupport {
 
-	private static final String COROUTINES_FLOW_CLASS_NAME = "kotlinx.coroutines.flow.Flow";
+	protected static final String COROUTINES_FLOW_CLASS_NAME = "kotlinx.coroutines.flow.Flow";
 
 	private final List<HttpMessageWriter<?>> messageWriters;
 

spring-webflux/src/main/java/org/springframework/web/reactive/result/method/annotation/ResponseEntityResultHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,6 +23,7 @@ import java.util.Set;
 
 import reactor.core.publisher.Mono;
 
+import org.springframework.core.KotlinDetector;
 import org.springframework.core.MethodParameter;
 import org.springframework.core.ReactiveAdapter;
 import org.springframework.core.ReactiveAdapterRegistry;
@@ -108,6 +109,7 @@ public class ResponseEntityResultHandler extends AbstractMessageWriterResultHand
 
 
 	@Override
+	@SuppressWarnings("ConstantConditions")
 	public Mono<Void> handleResult(ServerWebExchange exchange, HandlerResult result) {
 
 		Mono<?> returnValueMono;
@@ -118,7 +120,9 @@ public class ResponseEntityResultHandler extends AbstractMessageWriterResultHand
 		if (adapter != null) {
 			Assert.isTrue(!adapter.isMultiValue(), "Only a single ResponseEntity supported");
 			returnValueMono = Mono.from(adapter.toPublisher(result.getReturnValue()));
-			bodyParameter = actualParameter.nested().nested();
+			boolean isContinuation = (KotlinDetector.isSuspendingFunction(actualParameter.getMethod()) &&
+					!COROUTINES_FLOW_CLASS_NAME.equals(actualParameter.getParameterType().getName()));
+			bodyParameter = (isContinuation ? actualParameter.nested() : actualParameter.nested().nested());
 		}
 		else {
 			returnValueMono = Mono.justOrEmpty(result.getReturnValue());

spring-webflux/src/test/java/org/springframework/web/reactive/resource/ResourceWebHandlerTests.java

@@ -253,6 +253,23 @@ public class ResourceWebHandlerTests {
 		assertResponseBody(exchange, "h1 { color:red; }");
 	}
 
+	@Test  // gh-27538
+	public void filterNonExistingLocations() throws Exception {
+		List<Resource> inputLocations = Arrays.asList(
+				new ClassPathResource("test/", getClass()),
+				new ClassPathResource("testalternatepath/", getClass()),
+				new ClassPathResource("nosuchpath/", getClass()));
+
+		ResourceWebHandler handler = new ResourceWebHandler();
+		handler.setLocations(inputLocations);
+		handler.afterPropertiesSet();
+
+		List<Resource> actual = handler.getLocations();
+		assertThat(actual).hasSize(2);
+		assertThat(actual.get(0).getURL().toString()).endsWith("test/");
+		assertThat(actual.get(1).getURL().toString()).endsWith("testalternatepath/");
+	}
+
 	@Test // SPR-14577
 	public void getMediaTypeWithFavorPathExtensionOff() throws Exception {
 		List<Resource> paths = Collections.singletonList(new ClassPathResource("test/", getClass()));

spring-webflux/src/test/kotlin/org/springframework/web/reactive/result/method/annotation/CoroutinesIntegrationTests.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,18 +22,20 @@ import kotlinx.coroutines.async
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.flow
-import org.assertj.core.api.Assertions.*
+import org.assertj.core.api.Assertions.assertThat
+import org.assertj.core.api.Assertions.assertThatExceptionOfType
 import org.springframework.context.ApplicationContext
 import org.springframework.context.annotation.AnnotationConfigApplicationContext
 import org.springframework.context.annotation.ComponentScan
 import org.springframework.context.annotation.Configuration
 import org.springframework.http.HttpHeaders
 import org.springframework.http.HttpStatus
-import org.springframework.web.testfixture.http.server.reactive.bootstrap.HttpServer
+import org.springframework.http.ResponseEntity
 import org.springframework.web.bind.annotation.GetMapping
 import org.springframework.web.bind.annotation.RestController
 import org.springframework.web.client.HttpServerErrorException
 import org.springframework.web.reactive.config.EnableWebFlux
+import org.springframework.web.testfixture.http.server.reactive.bootstrap.HttpServer
 
 class CoroutinesIntegrationTests : AbstractRequestMappingIntegrationTests() {
 
@@ -63,6 +65,15 @@ class CoroutinesIntegrationTests : AbstractRequestMappingIntegrationTests() {
 		assertThat(entity.body).isEqualTo("foo")
 	}
 
+	@ParameterizedHttpServerTest  // gh-27292
+	fun `Suspending ResponseEntity handler method`(httpServer: HttpServer) {
+		startServer(httpServer)
+
+		val entity = performGet<String>("/suspend-response-entity", HttpHeaders.EMPTY, String::class.java)
+		assertThat(entity.statusCode).isEqualTo(HttpStatus.OK)
+		assertThat(entity.body).isEqualTo("{\"value\":\"foo\"}")
+	}
+
 	@ParameterizedHttpServerTest
 	fun `Handler method returning Flow`(httpServer: HttpServer) {
 		startServer(httpServer)
@@ -119,6 +130,12 @@ class CoroutinesIntegrationTests : AbstractRequestMappingIntegrationTests() {
 			"foo"
 		}
 
+		@GetMapping("/suspend-response-entity")
+		suspend fun suspendingResponseEntityEndpoint(): ResponseEntity<FooContainer<String>> {
+			delay(1)
+			return ResponseEntity.ok(FooContainer("foo"))
+		}
+
 		@GetMapping("/flow")
 		fun flowEndpoint()= flow {
 			emit("foo")
@@ -151,4 +168,8 @@ class CoroutinesIntegrationTests : AbstractRequestMappingIntegrationTests() {
 		}
 
 	}
+
+
+	class FooContainer<T>(val value: T)
+
 }

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/ResourceHttpRequestHandler.java

@@ -188,6 +188,9 @@ public class ResourceHttpRequestHandler extends WebContentGenerator
 	 * locations provided via {@link #setLocations(List) setLocations}.
 	 * <p>Note that the returned list is fully initialized only after
 	 * initialization via {@link #afterPropertiesSet()}.
+	 * <p><strong>Note:</strong> As of 5.3.11 the list of locations is filtered
+	 * to exclude those that don't actually exist and therefore the list returned
+	 * from this method may be a subset of all given locations.
 	 * @see #setLocationValues
 	 * @see #setLocations
 	 */
@@ -466,6 +469,7 @@ public class ResourceHttpRequestHandler extends WebContentGenerator
 		result.addAll(this.locationResources);
 		result = result.stream().filter(Resource::exists).collect(Collectors.toList());
 
+		this.locationsToUse.clear();
 		this.locationsToUse.addAll(result);
 	}