ResourceHttpRequestHandler initializes PathExtensionContentNegotiationStrategy in afterPropertiesSet

Issue: SPR-14851

spring-webmvc/src/main/java/org/springframework/web/servlet/config/annotation/ResourceHandlerRegistry.java

@@ -145,9 +145,8 @@ public class ResourceHandlerRegistry {
 				handler.setContentNegotiationManager(this.contentNegotiationManager);
 				try {
 					handler.afterPropertiesSet();
-					handler.afterSingletonsInstantiated();
 				}
-				catch (Exception ex) {
+				catch (Throwable ex) {
 					throw new BeanInitializationException("Failed to init ResourceHttpRequestHandler", ex);
 				}
 				urlMap.put(pathPattern, handler);

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

@@ -31,7 +31,6 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
 import org.springframework.beans.factory.InitializingBean;
-import org.springframework.beans.factory.SmartInitializingSingleton;
 import org.springframework.core.io.Resource;
 import org.springframework.core.io.support.ResourceRegion;
 import org.springframework.http.HttpHeaders;
@@ -91,7 +90,7 @@ import org.springframework.web.servlet.support.WebContentGenerator;
  * @since 3.0.4
  */
 public class ResourceHttpRequestHandler extends WebContentGenerator
-		implements HttpRequestHandler, InitializingBean, SmartInitializingSingleton, CorsConfigurationSource {
+		implements HttpRequestHandler, InitializingBean, CorsConfigurationSource {
 
 	// Servlet 3.1 setContentLengthLong(long) available?
 	private static final boolean contentLengthLongAvailable =
@@ -112,7 +111,7 @@ public class ResourceHttpRequestHandler extends WebContentGenerator
 
 	private ContentNegotiationManager contentNegotiationManager;
 
-	private PathExtensionContentNegotiationStrategy pathExtensionStrategy;
+	private PathExtensionContentNegotiationStrategy contentNegotiationStrategy;
 
 	private CorsConfiguration corsConfiguration;
 
@@ -253,16 +252,20 @@ public class ResourceHttpRequestHandler extends WebContentGenerator
 			logger.warn("Locations list is empty. No resources will be served unless a " +
 					"custom ResourceResolver is configured as an alternative to PathResourceResolver.");
 		}
+
 		if (this.resourceResolvers.isEmpty()) {
 			this.resourceResolvers.add(new PathResourceResolver());
 		}
 		initAllowedLocations();
+
 		if (this.resourceHttpMessageConverter == null) {
 			this.resourceHttpMessageConverter = new ResourceHttpMessageConverter();
 		}
 		if (this.resourceRegionHttpMessageConverter == null) {
 			this.resourceRegionHttpMessageConverter = new ResourceRegionHttpMessageConverter();
 		}
+
+		this.contentNegotiationStrategy = initContentNegotiationStrategy();
 	}
 
 	/**
@@ -285,11 +288,12 @@ public class ResourceHttpRequestHandler extends WebContentGenerator
 		}
 	}
 
-	@Override
-	public void afterSingletonsInstantiated() {
-		this.pathExtensionStrategy = initContentNegotiationStrategy();
-	}
-
+	/**
+	 * Initialize the content negotiation strategy depending on the {@code ContentNegotiationManager}
+	 * setup and the availability of a {@code ServletContext}.
+	 * @see ServletPathExtensionContentNegotiationStrategy
+	 * @see PathExtensionContentNegotiationStrategy
+	 */
 	protected PathExtensionContentNegotiationStrategy initContentNegotiationStrategy() {
 		Map<String, MediaType> mediaTypes = null;
 		if (getContentNegotiationManager() != null) {
@@ -299,9 +303,9 @@ public class ResourceHttpRequestHandler extends WebContentGenerator
 				mediaTypes = new HashMap<>(strategy.getMediaTypes());
 			}
 		}
-		return (getServletContext() != null) ?
-			new ServletPathExtensionContentNegotiationStrategy(getServletContext(), mediaTypes) :
-			new PathExtensionContentNegotiationStrategy(mediaTypes);
+		return (getServletContext() != null ?
+				new ServletPathExtensionContentNegotiationStrategy(getServletContext(), mediaTypes) :
+				new PathExtensionContentNegotiationStrategy(mediaTypes));
 	}
 
 
@@ -514,7 +518,7 @@ public class ResourceHttpRequestHandler extends WebContentGenerator
 	 * @return the corresponding media type, or {@code null} if none found
 	 */
 	protected MediaType getMediaType(HttpServletRequest request, Resource resource) {
-		return this.pathExtensionStrategy.getMediaTypeForResource(resource);
+		return this.contentNegotiationStrategy.getMediaTypeForResource(resource);
 	}
 
 	/**

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

@@ -81,7 +81,6 @@ public class ResourceHttpRequestHandlerTests {
 		this.handler.setCacheSeconds(3600);
 		this.handler.setServletContext(new TestServletContext());
 		this.handler.afterPropertiesSet();
-		this.handler.afterSingletonsInstantiated();
 
 		this.request = new MockHttpServletRequest("GET", "");
 		this.response = new MockHttpServletResponse();
@@ -148,7 +147,6 @@ public class ResourceHttpRequestHandlerTests {
 				.addFixedVersionStrategy("versionString", "/**");
 		this.handler.setResourceResolvers(Arrays.asList(versionResolver, new PathResourceResolver()));
 		this.handler.afterPropertiesSet();
-		this.handler.afterSingletonsInstantiated();
 
 		this.request.setAttribute(HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE, "versionString/foo.css");
 		this.handler.handleRequest(this.request, this.response);
@@ -255,7 +253,6 @@ public class ResourceHttpRequestHandlerTests {
 		handler.setLocations(paths);
 		handler.setContentNegotiationManager(manager);
 		handler.afterPropertiesSet();
-		handler.afterSingletonsInstantiated();
 
 		this.request.setAttribute(HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE, "foo.css");
 		handler.handleRequest(this.request, this.response);
@@ -277,7 +274,6 @@ public class ResourceHttpRequestHandlerTests {
 		handler.setLocations(paths);
 		handler.setContentNegotiationManager(manager);
 		handler.afterPropertiesSet();
-		handler.afterSingletonsInstantiated();
 
 		this.request.addHeader("Accept", "application/json,text/plain,*/*");
 		this.request.setAttribute(HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE, "foo.html");
@@ -306,7 +302,6 @@ public class ResourceHttpRequestHandlerTests {
 		handler.setServletContext(servletContext);
 		handler.setLocations(paths);
 		handler.afterPropertiesSet();
-		handler.afterSingletonsInstantiated();
 
 		this.request.setAttribute(HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE, "foo.css");
 		handler.handleRequest(this.request, this.response);
@@ -421,7 +416,6 @@ public class ResourceHttpRequestHandlerTests {
 		handler.setServletContext(new MockServletContext());
 		handler.setLocations(Arrays.asList(location1, location2));
 		handler.afterPropertiesSet();
-		handler.afterSingletonsInstantiated();
 
 		Resource[] locations = pathResolver.getAllowedLocations();
 		assertEquals(1, locations.length);