Fix ResourceUrlProvider handler auto-detection

Prior to this commit, `ResourceUrlProvider` would listen and consider
all `ContextRefreshedEvent` and use the given context to detect
`SimpleUrlHandlerMapping`.

This could lead to situations where a `ResourceUrlProvider` uses another
application context than its own (in a parent/child context setup) and
detect the wrong set of handlers.

Because `ResourceUrlProvider` locks itself once the auto-detection is
done, we need to ensure that it considers only events sent by its
application context.

Fixes gh-26562

spring-webflux/src/main/java/org/springframework/web/reactive/resource/ResourceUrlProvider.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.
@@ -26,12 +26,15 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import reactor.core.publisher.Mono;
 
+import org.springframework.beans.BeansException;
 import org.springframework.context.ApplicationContext;
+import org.springframework.context.ApplicationContextAware;
 import org.springframework.context.ApplicationListener;
 import org.springframework.context.event.ContextRefreshedEvent;
 import org.springframework.core.annotation.AnnotationAwareOrderComparator;
 import org.springframework.http.server.PathContainer;
 import org.springframework.http.server.reactive.ServerHttpRequest;
+import org.springframework.lang.Nullable;
 import org.springframework.util.StringUtils;
 import org.springframework.web.reactive.handler.SimpleUrlHandlerMapping;
 import org.springframework.web.server.ServerWebExchange;
@@ -47,15 +50,23 @@ import org.springframework.web.util.pattern.PathPatternParser;
  * {@code ResourceHttpRequestHandler}s to make its decisions.
  *
  * @author Rossen Stoyanchev
+ * @author Brian Clozel
  * @since 5.0
  */
-public class ResourceUrlProvider implements ApplicationListener<ContextRefreshedEvent> {
+public class ResourceUrlProvider implements ApplicationListener<ContextRefreshedEvent>, ApplicationContextAware {
 
 	private static final Log logger = LogFactory.getLog(ResourceUrlProvider.class);
 
 
 	private final Map<PathPattern, ResourceWebHandler> handlerMap = new LinkedHashMap<>();
 
+	@Nullable
+	private ApplicationContext applicationContext;
+
+	@Override
+	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
+		this.applicationContext = applicationContext;
+	}
 
 	/**
 	 * Return a read-only view of the resource handler mappings either manually
@@ -83,8 +94,8 @@ public class ResourceUrlProvider implements ApplicationListener<ContextRefreshed
 
 	@Override
 	public void onApplicationEvent(ContextRefreshedEvent event) {
-		if (this.handlerMap.isEmpty()) {
+		if (this.applicationContext == event.getApplicationContext() && this.handlerMap.isEmpty()) {
-			detectResourceHandlers(event.getApplicationContext());
+			detectResourceHandlers(this.applicationContext);
 		}
 	}
 

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

@@ -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.
@@ -44,6 +44,7 @@ import static org.springframework.web.testfixture.http.server.reactive.MockServe
  * Unit tests for {@link ResourceUrlProvider}.
  *
  * @author Rossen Stoyanchev
+ * @author Brian Clozel
  */
 public class ResourceUrlProviderTests {
 
@@ -62,7 +63,7 @@ public class ResourceUrlProviderTests {
 
 
 	@BeforeEach
-	public void setup() throws Exception {
+	void setup() throws Exception {
 		this.locations.add(new ClassPathResource("test/", getClass()));
 		this.locations.add(new ClassPathResource("testalternatepath/", getClass()));
 		this.handler.setLocations(this.locations);
@@ -73,7 +74,7 @@ public class ResourceUrlProviderTests {
 
 
 	@Test
-	public void getStaticResourceUrl() {
+	void getStaticResourceUrl() {
 		String expected = "/resources/foo.css";
 		String actual = this.urlProvider.getForUriString(expected, this.exchange).block(TIMEOUT);
 
@@ -81,7 +82,7 @@ public class ResourceUrlProviderTests {
 	}
 
 	@Test  // SPR-13374
-	public void getStaticResourceUrlRequestWithQueryOrHash() {
+	void getStaticResourceUrlRequestWithQueryOrHash() {
 
 		String url = "/resources/foo.css?foo=bar&url=https://example.org";
 		String resolvedUrl = this.urlProvider.getForUriString(url, this.exchange).block(TIMEOUT);
@@ -93,7 +94,7 @@ public class ResourceUrlProviderTests {
 	}
 
 	@Test
-	public void getVersionedResourceUrl() {
+	void getVersionedResourceUrl() {
 		VersionResourceResolver versionResolver = new VersionResourceResolver();
 		versionResolver.setStrategyMap(Collections.singletonMap("/**", new ContentVersionStrategy()));
 		List<ResourceResolver> resolvers = new ArrayList<>();
@@ -108,7 +109,7 @@ public class ResourceUrlProviderTests {
 	}
 
 	@Test  // SPR-12647
-	public void bestPatternMatch() {
+	void bestPatternMatch() {
 		ResourceWebHandler otherHandler = new ResourceWebHandler();
 		otherHandler.setLocations(this.locations);
 
@@ -129,7 +130,7 @@ public class ResourceUrlProviderTests {
 
 	@Test  // SPR-12592
 	@SuppressWarnings("resource")
-	public void initializeOnce() {
+	void initializeOnce() {
 		AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
 		context.setServletContext(new MockServletContext());
 		context.register(HandlerMappingConfiguration.class);
@@ -139,6 +140,26 @@ public class ResourceUrlProviderTests {
 				.hasKeySatisfying(pathPatternStringOf("/resources/**"));
 	}
 
+	@Test
+	void initializeOnCurrentContext() {
+		AnnotationConfigWebApplicationContext parentContext = new AnnotationConfigWebApplicationContext();
+		parentContext.setServletContext(new MockServletContext());
+		parentContext.register(ParentHandlerMappingConfiguration.class);
+
+		AnnotationConfigWebApplicationContext childContext = new AnnotationConfigWebApplicationContext();
+		childContext.setParent(parentContext);
+		childContext.setServletContext(new MockServletContext());
+		childContext.register(HandlerMappingConfiguration.class);
+
+		parentContext.refresh();
+		childContext.refresh();
+
+		ResourceUrlProvider parentUrlProvider = parentContext.getBean(ResourceUrlProvider.class);
+		assertThat(parentUrlProvider.getHandlerMap()).isEmpty();
+		ResourceUrlProvider childUrlProvider = childContext.getBean(ResourceUrlProvider.class);
+		assertThat(childUrlProvider.getHandlerMap()).hasKeySatisfying(pathPatternStringOf("/resources/**"));
+	}
+
 
 	private Condition<PathPattern> pathPatternStringOf(String expected) {
 		return new Condition<PathPattern>(
@@ -161,4 +182,14 @@ public class ResourceUrlProviderTests {
 		}
 	}
 
+	@Configuration
+	@SuppressWarnings({"unused", "WeakerAccess"})
+	static class ParentHandlerMappingConfiguration {
+
+		@Bean
+		public ResourceUrlProvider resourceUrlProvider() {
+			return new ResourceUrlProvider();
+		}
+	}
+
 }

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/ResourceUrlProvider.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.
@@ -27,7 +27,9 @@ import javax.servlet.http.HttpServletRequest;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
+import org.springframework.beans.BeansException;
 import org.springframework.context.ApplicationContext;
+import org.springframework.context.ApplicationContextAware;
 import org.springframework.context.ApplicationListener;
 import org.springframework.context.event.ContextRefreshedEvent;
 import org.springframework.core.annotation.AnnotationAwareOrderComparator;
@@ -48,12 +50,16 @@ import org.springframework.web.util.UrlPathHelper;
  * {@code ResourceHttpRequestHandler}s to make its decisions.
  *
  * @author Rossen Stoyanchev
+ * @author Brian Clozel
  * @since 4.1
  */
-public class ResourceUrlProvider implements ApplicationListener<ContextRefreshedEvent> {
+public class ResourceUrlProvider implements ApplicationListener<ContextRefreshedEvent>, ApplicationContextAware {
 
 	protected final Log logger = LogFactory.getLog(getClass());
 
+	@Nullable
+	private ApplicationContext applicationContext;
+
 	private UrlPathHelper urlPathHelper = UrlPathHelper.defaultInstance;
 
 	private PathMatcher pathMatcher = new AntPathMatcher();
@@ -62,6 +68,10 @@ public class ResourceUrlProvider implements ApplicationListener<ContextRefreshed
 
 	private boolean autodetect = true;
 
+	@Override
+	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
+		this.applicationContext = applicationContext;
+	}
 
 	/**
 	 * Configure a {@code UrlPathHelper} to use in
@@ -127,9 +137,9 @@ public class ResourceUrlProvider implements ApplicationListener<ContextRefreshed
 
 	@Override
 	public void onApplicationEvent(ContextRefreshedEvent event) {
-		if (isAutodetect()) {
+		if (event.getApplicationContext() == this.applicationContext && isAutodetect()) {
 			this.handlerMap.clear();
-			detectResourceHandlers(event.getApplicationContext());
+			detectResourceHandlers(this.applicationContext);
 			if (!this.handlerMap.isEmpty()) {
 				this.autodetect = false;
 			}

spring-webmvc/src/test/java/org/springframework/web/servlet/resource/ResourceUrlProviderTests.java

@@ -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.
@@ -44,6 +44,7 @@ import static org.mockito.Mockito.mock;
  *
  * @author Jeremy Grelle
  * @author Rossen Stoyanchev
+ * @author Brian Clozel
  */
 public class ResourceUrlProviderTests {
 
@@ -57,7 +58,7 @@ public class ResourceUrlProviderTests {
 
 
 	@BeforeEach
-	public void setUp() throws Exception {
+	void setUp() throws Exception {
 		this.locations.add(new ClassPathResource("test/", getClass()));
 		this.locations.add(new ClassPathResource("testalternatepath/", getClass()));
 		this.handler.setServletContext(new MockServletContext());
@@ -69,13 +70,13 @@ public class ResourceUrlProviderTests {
 
 
 	@Test
-	public void getStaticResourceUrl() {
+	void getStaticResourceUrl() {
 		String url = this.urlProvider.getForLookupPath("/resources/foo.css");
 		assertThat(url).isEqualTo("/resources/foo.css");
 	}
 
 	@Test // SPR-13374
-	public void getStaticResourceUrlRequestWithQueryOrHash() {
+	void getStaticResourceUrlRequestWithQueryOrHash() {
 		MockHttpServletRequest request = new MockHttpServletRequest();
 		request.setContextPath("/");
 		request.setRequestURI("/");
@@ -90,7 +91,7 @@ public class ResourceUrlProviderTests {
 	}
 
 	@Test // SPR-16526
-	public void getStaticResourceWithMissingContextPath() {
+	void getStaticResourceWithMissingContextPath() {
 		MockHttpServletRequest request = new MockHttpServletRequest();
 		request.setContextPath("/contextpath-longer-than-request-path");
 		request.setRequestURI("/contextpath-longer-than-request-path/style.css");
@@ -100,7 +101,7 @@ public class ResourceUrlProviderTests {
 	}
 
 	@Test
-	public void getFingerprintedResourceUrl() {
+	void getFingerprintedResourceUrl() {
 		Map<String, VersionStrategy> versionStrategyMap = new HashMap<>();
 		versionStrategyMap.put("/**", new ContentVersionStrategy());
 		VersionResourceResolver versionResolver = new VersionResourceResolver();
@@ -116,7 +117,7 @@ public class ResourceUrlProviderTests {
 	}
 
 	@Test // SPR-12647
-	public void bestPatternMatch() throws Exception {
+	void bestPatternMatch() throws Exception {
 		ResourceHttpRequestHandler otherHandler = new ResourceHttpRequestHandler();
 		otherHandler.setLocations(this.locations);
 		Map<String, VersionStrategy> versionStrategyMap = new HashMap<>();
@@ -138,7 +139,7 @@ public class ResourceUrlProviderTests {
 
 	@Test // SPR-12592
 	@SuppressWarnings("resource")
-	public void initializeOnce() throws Exception {
+	void initializeOnce() throws Exception {
 		AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
 		context.setServletContext(new MockServletContext());
 		context.register(HandlerMappingConfiguration.class);
@@ -149,8 +150,30 @@ public class ResourceUrlProviderTests {
 		assertThat(urlProviderBean.isAutodetect()).isFalse();
 	}
 
+	@Test
+	void initializeOnCurrentContext() {
+		AnnotationConfigWebApplicationContext parentContext = new AnnotationConfigWebApplicationContext();
+		parentContext.setServletContext(new MockServletContext());
+		parentContext.register(ParentHandlerMappingConfiguration.class);
+
+		AnnotationConfigWebApplicationContext childContext = new AnnotationConfigWebApplicationContext();
+		childContext.setParent(parentContext);
+		childContext.setServletContext(new MockServletContext());
+		childContext.register(HandlerMappingConfiguration.class);
+
+		parentContext.refresh();
+		childContext.refresh();
+
+		ResourceUrlProvider parentUrlProvider = parentContext.getBean(ResourceUrlProvider.class);
+		assertThat(parentUrlProvider.getHandlerMap()).isEmpty();
+		assertThat(parentUrlProvider.isAutodetect()).isTrue();
+		ResourceUrlProvider childUrlProvider = childContext.getBean(ResourceUrlProvider.class);
+		assertThat(childUrlProvider.getHandlerMap()).containsOnlyKeys("/resources/**");
+		assertThat(childUrlProvider.isAutodetect()).isFalse();
+	}
+
 	@Test // SPR-16296
-	public void getForLookupPathShouldNotFailIfPathContainsDoubleSlashes() {
+	void getForLookupPathShouldNotFailIfPathContainsDoubleSlashes() {
 		// given
 		ResourceResolver mockResourceResolver = mock(ResourceResolver.class);
 		given(mockResourceResolver.resolveUrlPath(any(), any(), any())).willReturn("some-path");
@@ -185,4 +208,14 @@ public class ResourceUrlProviderTests {
 		}
 	}
 
+	@Configuration
+	@SuppressWarnings({"unused", "WeakerAccess"})
+	static class ParentHandlerMappingConfiguration {
+
+		@Bean
+		public ResourceUrlProvider resourceUrlProvider() {
+			return new ResourceUrlProvider();
+		}
+	}
+
 }