Deprecate resource "app-cache" configuration support

This commit deprecates the
`"spring.resources.chain.html-application-cache"` configuration property
and its support, since the feature has been deprecated in Spring
Framework.

The app-cache manifest feature is being removed from browsers in favor
of web workers.

Closes gh-23228

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -21,6 +21,7 @@ import java.time.temporal.ChronoUnit;
 import java.util.concurrent.TimeUnit;
 
 import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.boot.context.properties.DeprecatedConfigurationProperty;
 import org.springframework.boot.context.properties.PropertyMapper;
 import org.springframework.boot.convert.DurationUnit;
 import org.springframework.http.CacheControl;
@@ -145,6 +146,8 @@ public class ResourceProperties {
 			return this.strategy;
 		}
 
+		@DeprecatedConfigurationProperty(reason = "The appcache manifest feature is being removed from browsers.")
+		@Deprecated
 		public boolean isHtmlApplicationCache() {
 			return this.htmlApplicationCache;
 		}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/reactive/ResourceChainResourceHandlerRegistrationCustomizer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -20,7 +20,6 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.web.ResourceProperties;
 import org.springframework.web.reactive.config.ResourceChainRegistration;
 import org.springframework.web.reactive.config.ResourceHandlerRegistration;
-import org.springframework.web.reactive.resource.AppCacheManifestTransformer;
 import org.springframework.web.reactive.resource.EncodedResourceResolver;
 import org.springframework.web.reactive.resource.ResourceResolver;
 import org.springframework.web.reactive.resource.VersionResourceResolver;
@@ -42,6 +41,7 @@ class ResourceChainResourceHandlerRegistrationCustomizer implements ResourceHand
 		configureResourceChain(properties, registration.resourceChain(properties.isCache()));
 	}
 
+	@SuppressWarnings("deprecation")
 	private void configureResourceChain(ResourceProperties.Chain properties, ResourceChainRegistration chain) {
 		ResourceProperties.Strategy strategy = properties.getStrategy();
 		if (properties.isCompressed()) {
@@ -51,7 +51,7 @@ class ResourceChainResourceHandlerRegistrationCustomizer implements ResourceHand
 			chain.addResolver(getVersionResourceResolver(strategy));
 		}
 		if (properties.isHtmlApplicationCache()) {
-			chain.addTransformer(new AppCacheManifestTransformer());
+			chain.addTransformer(new org.springframework.web.reactive.resource.AppCacheManifestTransformer());
 		}
 	}
 

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

@@ -111,7 +111,6 @@ import org.springframework.web.servlet.i18n.FixedLocaleResolver;
 import org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver;
 import org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter;
 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.ResourceResolver;
 import org.springframework.web.servlet.resource.ResourceUrlProvider;
@@ -564,6 +563,7 @@ public class WebMvcAutoConfiguration {
 			configureResourceChain(properties, registration.resourceChain(properties.isCache()));
 		}
 
+		@SuppressWarnings("deprecation")
 		private void configureResourceChain(ResourceProperties.Chain properties, ResourceChainRegistration chain) {
 			Strategy strategy = properties.getStrategy();
 			if (properties.isCompressed()) {
@@ -573,7 +573,7 @@ public class WebMvcAutoConfiguration {
 				chain.addResolver(getVersionResourceResolver(strategy));
 			}
 			if (properties.isHtmlApplicationCache()) {
-				chain.addTransformer(new AppCacheManifestTransformer());
+				chain.addTransformer(new org.springframework.web.servlet.resource.AppCacheManifestTransformer());
 			}
 		}
 

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

@@ -105,7 +105,6 @@ import org.springframework.web.servlet.i18n.FixedLocaleResolver;
 import org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter;
 import org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping;
 import org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver;
-import org.springframework.web.servlet.resource.AppCacheManifestTransformer;
 import org.springframework.web.servlet.resource.CachingResourceResolver;
 import org.springframework.web.servlet.resource.CachingResourceTransformer;
 import org.springframework.web.servlet.resource.ContentVersionStrategy;
@@ -255,6 +254,7 @@ class WebMvcAutoConfigurationTests {
 	}
 
 	@Test
+	@SuppressWarnings("deprecation")
 	void resourceHandlerChainCustomized() {
 		this.contextRunner
 				.withPropertyValues("spring.resources.chain.enabled:true", "spring.resources.chain.cache:false",
@@ -269,8 +269,9 @@ class WebMvcAutoConfigurationTests {
 					assertThat(getResourceTransformers(context, "/webjars/**")).hasSize(2);
 					assertThat(getResourceResolvers(context, "/**")).extractingResultOf("getClass").containsOnly(
 							EncodedResourceResolver.class, VersionResourceResolver.class, PathResourceResolver.class);
-					assertThat(getResourceTransformers(context, "/**")).extractingResultOf("getClass")
-							.containsOnly(CssLinkResourceTransformer.class, AppCacheManifestTransformer.class);
+					assertThat(getResourceTransformers(context, "/**")).extractingResultOf("getClass").containsOnly(
+							CssLinkResourceTransformer.class,
+							org.springframework.web.servlet.resource.AppCacheManifestTransformer.class);
 					VersionResourceResolver resolver = (VersionResourceResolver) getResourceResolvers(context, "/**")
 							.get(1);
 					Map<String, VersionStrategy> strategyMap = resolver.getStrategyMap();