Allow custom resource handlers to provide favicon.ico

Closes gh-17381

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration.java

@@ -17,9 +17,7 @@
 package org.springframework.boot.autoconfigure.web.servlet;
 
 import java.time.Duration;
-import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Collections;
 import java.util.List;
 import java.util.ListIterator;
 import java.util.Map;
@@ -66,7 +64,6 @@ import org.springframework.context.annotation.Import;
 import org.springframework.context.annotation.Primary;
 import org.springframework.core.Ordered;
 import org.springframework.core.annotation.Order;
-import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.Resource;
 import org.springframework.core.io.ResourceLoader;
 import org.springframework.core.task.AsyncTaskExecutor;
@@ -106,7 +103,6 @@ import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
 import org.springframework.web.servlet.handler.AbstractHandlerExceptionResolver;
-import org.springframework.web.servlet.handler.SimpleUrlHandlerMapping;
 import org.springframework.web.servlet.i18n.AcceptHeaderLocaleResolver;
 import org.springframework.web.servlet.i18n.FixedLocaleResolver;
 import org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver;
@@ -114,7 +110,6 @@ import org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandl
 import org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping;
 import org.springframework.web.servlet.resource.AppCacheManifestTransformer;
 import org.springframework.web.servlet.resource.EncodedResourceResolver;
-import org.springframework.web.servlet.resource.ResourceHttpRequestHandler;
 import org.springframework.web.servlet.resource.ResourceResolver;
 import org.springframework.web.servlet.resource.ResourceUrlProvider;
 import org.springframework.web.servlet.resource.VersionResourceResolver;
@@ -370,48 +365,13 @@ public class WebMvcAutoConfiguration {
 
 		@Configuration(proxyBeanMethods = false)
 		@ConditionalOnProperty(value = "spring.mvc.favicon.enabled", matchIfMissing = true)
-		public static class FaviconConfiguration implements ResourceLoaderAware {
-
-			private final ResourceProperties resourceProperties;
-
-			private ResourceLoader resourceLoader;
-
-			public FaviconConfiguration(ResourceProperties resourceProperties) {
-				this.resourceProperties = resourceProperties;
-			}
+		public static class FaviconConfiguration implements WebMvcConfigurer {
 
 			@Override
-			public void setResourceLoader(ResourceLoader resourceLoader) {
-				this.resourceLoader = resourceLoader;
-			}
-
-			@Bean
-			public SimpleUrlHandlerMapping faviconHandlerMapping(FaviconRequestHandler handler) {
-				SimpleUrlHandlerMapping mapping = new SimpleUrlHandlerMapping();
-				mapping.setOrder(Ordered.HIGHEST_PRECEDENCE + 1);
-				mapping.setUrlMap(Collections.singletonMap("**/favicon.ico", handler));
-				return mapping;
-			}
-
-			@Bean
-			public FaviconRequestHandler faviconRequestHandler() {
-				return new FaviconRequestHandler(resolveFaviconLocations());
-			}
-
-			private List<Resource> resolveFaviconLocations() {
-				String[] staticLocations = getResourceLocations(this.resourceProperties.getStaticLocations());
-				List<Resource> locations = new ArrayList<>(staticLocations.length + 1);
-				Arrays.stream(staticLocations).map(this.resourceLoader::getResource).forEach(locations::add);
-				locations.add(new ClassPathResource("/"));
-				return Collections.unmodifiableList(locations);
-			}
-
-		}
-
-		static final class FaviconRequestHandler extends ResourceHttpRequestHandler {
-
-			FaviconRequestHandler(List<Resource> locations) {
-				setLocations(locations);
+			public void addResourceHandlers(ResourceHandlerRegistry registry) {
+				if (!registry.hasMappingForPattern("favicon.ico")) {
+					registry.addResourceHandler("favicon.ico").addResourceLocations("classpath:favicon.ico");
+				}
 			}
 
 		}

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfigurationTests.java

@@ -24,6 +24,7 @@ import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.concurrent.Executor;
 import java.util.concurrent.TimeUnit;
 import java.util.function.Consumer;
@@ -147,7 +148,7 @@ class WebMvcAutoConfigurationTests {
 
 	@Test
 	void handlerMappingsCreated() {
-		this.contextRunner.run((context) -> assertThat(context).getBeans(HandlerMapping.class).hasSize(6));
+		this.contextRunner.run((context) -> assertThat(context).getBeans(HandlerMapping.class).hasSize(5));
 	}
 
 	@Test
@@ -195,7 +196,7 @@ class WebMvcAutoConfigurationTests {
 	@Test
 	void resourceHandlerMappingDisabled() {
 		this.contextRunner.withPropertyValues("spring.resources.add-mappings:false")
-				.run((context) -> assertThat(context.getBean("resourceHandlerMapping")).isEqualTo(null));
+				.run((context) -> assertThat(getResourceMappingLocations(context)).hasSize(1));
 	}
 
 	@Test
@@ -379,25 +380,14 @@ class WebMvcAutoConfigurationTests {
 
 	@Test
 	void faviconMapping() {
-		this.contextRunner.run((context) -> {
-			assertThat(context).getBeanNames(ResourceHttpRequestHandler.class).contains("faviconRequestHandler");
-			assertThat(context).getBeans(SimpleUrlHandlerMapping.class).containsKey("faviconHandlerMapping");
-			assertThat(getFaviconMappingLocations(context).get("/**/favicon.ico")).hasSize(6);
-		});
-	}
-
-	@Test
-	void faviconMappingUsesStaticLocations() {
-		this.contextRunner.withPropertyValues("spring.resources.static-locations=classpath:/static")
-				.run((context) -> assertThat(getFaviconMappingLocations(context).get("/**/favicon.ico")).hasSize(3));
+		this.contextRunner
+				.run((context) -> assertThat(getResourceMappingLocations(context).get("/favicon.ico")).hasSize(1));
 	}
 
 	@Test
 	void faviconMappingDisabled() {
-		this.contextRunner.withPropertyValues("spring.mvc.favicon.enabled:false").run((context) -> {
-			assertThat(context).getBeans(ResourceHttpRequestHandler.class).doesNotContainKey("faviconRequestHandler");
-			assertThat(context).getBeans(SimpleUrlHandlerMapping.class).doesNotContainKey("faviconHandlerMapping");
-		});
+		this.contextRunner.withPropertyValues("spring.mvc.favicon.enabled:false")
+				.run((context) -> assertThat(getResourceMappingLocations(context).get("/favicon.ico")).isNull());
 	}
 
 	@Test
@@ -667,11 +657,14 @@ class WebMvcAutoConfigurationTests {
 
 	private void assertCachePeriod(AssertableWebApplicationContext context) {
 		Map<String, Object> handlerMap = getHandlerMap(context.getBean("resourceHandlerMapping", HandlerMapping.class));
-		assertThat(handlerMap).hasSize(2);
-		for (Object handler : handlerMap.values()) {
-			if (handler instanceof ResourceHttpRequestHandler) {
-				assertThat(((ResourceHttpRequestHandler) handler).getCacheSeconds()).isEqualTo(5);
-				assertThat(((ResourceHttpRequestHandler) handler).getCacheControl()).isNull();
+		assertThat(handlerMap).hasSize(3);
+		for (Entry<String, Object> entry : handlerMap.entrySet()) {
+			if (!entry.getKey().equals("/favicon.ico")) {
+				Object handler = entry.getValue();
+				if (handler instanceof ResourceHttpRequestHandler) {
+					assertThat(((ResourceHttpRequestHandler) handler).getCacheSeconds()).isEqualTo(5);
+					assertThat(((ResourceHttpRequestHandler) handler).getCacheControl()).isNull();
+				}
 			}
 		}
 	}
@@ -788,7 +781,7 @@ class WebMvcAutoConfigurationTests {
 
 	private void assertCacheControl(AssertableWebApplicationContext context) {
 		Map<String, Object> handlerMap = getHandlerMap(context.getBean("resourceHandlerMapping", HandlerMapping.class));
-		assertThat(handlerMap).hasSize(2);
+		assertThat(handlerMap).hasSize(3);
 		for (Object handler : handlerMap.keySet()) {
 			if (handler instanceof ResourceHttpRequestHandler) {
 				assertThat(((ResourceHttpRequestHandler) handler).getCacheSeconds()).isEqualTo(-1);
@@ -798,10 +791,6 @@ class WebMvcAutoConfigurationTests {
 		}
 	}
 
-	protected Map<String, List<Resource>> getFaviconMappingLocations(ApplicationContext context) {
-		return getMappingLocations(context.getBean("faviconHandlerMapping", HandlerMapping.class));
-	}
-
 	protected Map<String, List<Resource>> getResourceMappingLocations(ApplicationContext context) {
 		return getMappingLocations(context.getBean("resourceHandlerMapping", HandlerMapping.class));
 	}