Add CacheControl config keys in spring.resources.*

This commit adds several configuration keys for customizing the
"Cache-Control" HTTP response header when serving static resources.

New keys are located in the "spring.resources.cache-control.*"
namespace; anything configured there will prevail on existing
"spring.resources.cache-period=" values, so as to mirror Spring MVC's
behavior.

Fixes gh-9432

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

@@ -18,9 +18,17 @@ package org.springframework.boot.autoconfigure.web;
 
 import java.time.Duration;
 import java.time.temporal.ChronoUnit;
+import java.util.concurrent.TimeUnit;
+import java.util.function.BiFunction;
+import java.util.function.Supplier;
+
+import javax.annotation.PostConstruct;
 
 import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.boot.context.properties.NestedConfigurationProperty;
 import org.springframework.boot.context.properties.bind.convert.DurationUnit;
+import org.springframework.http.CacheControl;
+import org.springframework.util.Assert;
 
 /**
  * Properties used to configure resource handling.
@@ -29,6 +37,7 @@ import org.springframework.boot.context.properties.bind.convert.DurationUnit;
  * @author Brian Clozel
  * @author Dave Syer
  * @author Venil Noronha
+ * @author Kristine Jetzke
  * @since 1.1.0
  */
 @ConfigurationProperties(prefix = "spring.resources", ignoreUnknownFields = false)
@@ -36,7 +45,7 @@ public class ResourceProperties {
 
 	private static final String[] CLASSPATH_RESOURCE_LOCATIONS = {
 			"classpath:/META-INF/resources/", "classpath:/resources/",
-			"classpath:/static/", "classpath:/public/" };
+			"classpath:/static/", "classpath:/public/"};
 
 	/**
 	 * Locations of static resources. Defaults to classpath:[/META-INF/resources/,
@@ -51,6 +60,12 @@ public class ResourceProperties {
 	@DurationUnit(ChronoUnit.SECONDS)
 	private Duration cachePeriod;
 
+	/**
+	 * Cache control headers. Either {@link #cachePeriod} or {@link #cacheControl} can be set.
+	 */
+	@NestedConfigurationProperty
+	private CacheControlProperties cacheControl;
+
 	/**
 	 * Enable default resource handling.
 	 */
@@ -83,6 +98,15 @@ public class ResourceProperties {
 		this.cachePeriod = cachePeriod;
 	}
 
+	public CacheControlProperties getCacheControl() {
+		return this.cacheControl;
+	}
+
+	public void setCacheControl(CacheControlProperties cacheControl) {
+		this.cacheControl = cacheControl;
+	}
+
+
 	public boolean isAddMappings() {
 		return this.addMappings;
 	}
@@ -95,6 +119,36 @@ public class ResourceProperties {
 		return this.chain;
 	}
 
+	public CacheControl createCacheControl() {
+		if (this.cachePeriod != null) {
+			return CacheControl.maxAge(this.cachePeriod.getSeconds(), TimeUnit.SECONDS);
+		}
+		if (this.cacheControl != null) {
+			return this.cacheControl.transformToHttpSpringCacheControl();
+		}
+		return null;
+	}
+
+	@PostConstruct
+	public void checkIncompatibleCacheOptions() {
+		Assert.state(this.cachePeriod == null || this.cacheControl == null,
+				"Only one of cache-period or cache-control may be set.");
+		if (this.cacheControl != null) {
+			if (this.cacheControl.getMaxAge() != null) {
+				Assert.state(!Boolean.TRUE.equals(this.cacheControl.getNoCache()), "no-cache may not be set if max-age is set.");
+				Assert.state(!Boolean.TRUE.equals(this.cacheControl.getNoStore()), "no-store may not be set if max-age is set.");
+			}
+			if (this.cacheControl.getNoCache() != null) {
+				Assert.state(this.cacheControl.getMaxAge() == null, "max-age may not be set if no-cache is set.");
+				Assert.state(!Boolean.TRUE.equals(this.cacheControl.getNoStore()), "no-store may not be set if no-cache is set.");
+			}
+			if (this.cacheControl.getNoStore() != null) {
+				Assert.state(this.cacheControl.getMaxAge() == null, "max-age may not be set if no-store is set.");
+				Assert.state(!Boolean.TRUE.equals(this.cacheControl.getNoCache()), "no-cache may not be set if no-store is set.");
+			}
+		}
+	}
+
 	/**
 	 * Configuration for the Spring Resource Handling chain.
 	 */
@@ -127,8 +181,9 @@ public class ResourceProperties {
 		/**
 		 * Return whether the resource chain is enabled. Return {@code null} if no
 		 * specific settings are present.
-		 * @return whether the resource chain is enabled or {@code null} if no specified
-		 * settings are present.
+		 *
+		 * @return whether the resource chain is enabled or {@code null} if no specified settings are
+		 * present.
 		 */
 		public Boolean getEnabled() {
 			return getEnabled(getStrategy().getFixed().isEnabled(),
@@ -206,7 +261,7 @@ public class ResourceProperties {
 		/**
 		 * Comma-separated list of patterns to apply to the Version Strategy.
 		 */
-		private String[] paths = new String[] { "/**" };
+		private String[] paths = new String[]{"/**"};
 
 		public boolean isEnabled() {
 			return this.enabled;
@@ -239,7 +294,7 @@ public class ResourceProperties {
 		/**
 		 * Comma-separated list of patterns to apply to the Version Strategy.
 		 */
-		private String[] paths = new String[] { "/**" };
+		private String[] paths = new String[]{"/**"};
 
 		/**
 		 * Version string to use for the Version Strategy.
@@ -272,4 +327,183 @@ public class ResourceProperties {
 
 	}
 
+	/**
+	 * Configuration for the Cache Control header.
+	 */
+
+	public static class CacheControlProperties {
+
+		private Long maxAge;
+
+		private Boolean noCache;
+
+		private Boolean noStore;
+
+		private Boolean mustRevalidate;
+
+		private Boolean noTransform;
+
+		private Boolean cachePublic;
+
+		private Boolean cachePrivate;
+
+		private Boolean proxyRevalidate;
+
+		private Long staleWhileRevalidate;
+
+		private Long staleIfError;
+
+		private Long sMaxAge;
+
+		public Long getMaxAge() {
+			return this.maxAge;
+		}
+
+		public void setMaxAge(Long maxAge) {
+			this.maxAge = maxAge;
+		}
+
+		public Boolean getNoCache() {
+			return this.noCache;
+		}
+
+		public void setNoCache(Boolean noCache) {
+			this.noCache = noCache;
+		}
+
+		public Boolean getNoStore() {
+			return this.noStore;
+		}
+
+		public void setNoStore(Boolean noStore) {
+			this.noStore = noStore;
+		}
+
+		public Boolean getMustRevalidate() {
+			return this.mustRevalidate;
+		}
+
+		public void setMustRevalidate(Boolean mustRevalidate) {
+			this.mustRevalidate = mustRevalidate;
+		}
+
+		public Boolean getNoTransform() {
+			return this.noTransform;
+		}
+
+		public void setNoTransform(Boolean noTransform) {
+			this.noTransform = noTransform;
+		}
+
+		public Boolean getCachePublic() {
+			return this.cachePublic;
+		}
+
+		public void setCachePublic(Boolean cachePublic) {
+			this.cachePublic = cachePublic;
+		}
+
+		public Boolean getCachePrivate() {
+			return this.cachePrivate;
+		}
+
+		public void setCachePrivate(Boolean cachePrivate) {
+			this.cachePrivate = cachePrivate;
+		}
+
+		public Boolean getProxyRevalidate() {
+			return this.proxyRevalidate;
+		}
+
+		public void setProxyRevalidate(Boolean proxyRevalidate) {
+			this.proxyRevalidate = proxyRevalidate;
+		}
+
+		public Long getStaleWhileRevalidate() {
+			return this.staleWhileRevalidate;
+		}
+
+		public void setStaleWhileRevalidate(Long staleWhileRevalidate) {
+			this.staleWhileRevalidate = staleWhileRevalidate;
+		}
+
+		public Long getStaleIfError() {
+			return this.staleIfError;
+		}
+
+		public void setStaleIfError(Long staleIfError) {
+			this.staleIfError = staleIfError;
+		}
+
+		public Long getsMaxAge() {
+			return this.sMaxAge;
+		}
+
+		public void setsMaxAge(Long sMaxAge) {
+			this.sMaxAge = sMaxAge;
+		}
+
+		CacheControl transformToHttpSpringCacheControl() {
+			CacheControl httpSpringCacheControl = initCacheControl();
+			httpSpringCacheControl = setFlags(httpSpringCacheControl);
+			httpSpringCacheControl = setTimes(httpSpringCacheControl);
+			return httpSpringCacheControl;
+		}
+
+		private CacheControl initCacheControl() {
+			if (this.maxAge != null) {
+				return CacheControl.maxAge(this.maxAge, TimeUnit.SECONDS);
+			}
+			if (Boolean.TRUE.equals(this.noCache)) {
+				return CacheControl.noCache();
+			}
+			if (Boolean.TRUE.equals(this.noStore)) {
+				return CacheControl.noStore();
+			}
+			return CacheControl.empty();
+		}
+
+		private CacheControl setFlags(CacheControl cacheControl) {
+			cacheControl = setBoolean(this.mustRevalidate, cacheControl::mustRevalidate,
+					cacheControl);
+			cacheControl = setBoolean(this.noTransform, cacheControl::noTransform,
+					cacheControl);
+			cacheControl = setBoolean(this.cachePublic, cacheControl::cachePublic,
+					cacheControl);
+			cacheControl = setBoolean(this.cachePrivate, cacheControl::cachePrivate,
+					cacheControl);
+			cacheControl = setBoolean(this.proxyRevalidate, cacheControl::proxyRevalidate,
+					cacheControl);
+			return cacheControl;
+		}
+
+		private static CacheControl setBoolean(Boolean value,
+				Supplier<CacheControl> setter, CacheControl cacheControl) {
+			if (Boolean.TRUE.equals(value)) {
+				return setter.get();
+			}
+			return cacheControl;
+		}
+
+		private CacheControl setTimes(CacheControl cacheControl) {
+			cacheControl = setLong(this.staleWhileRevalidate,
+					cacheControl::staleWhileRevalidate, cacheControl);
+			cacheControl = setLong(this.staleIfError, cacheControl::staleIfError,
+					cacheControl);
+			cacheControl = setLong(this.sMaxAge, cacheControl::sMaxAge, cacheControl);
+			return cacheControl;
+		}
+
+		private static CacheControl setLong(Long value,
+				BiFunction<Long, TimeUnit, CacheControl> setter,
+				CacheControl cacheControl) {
+			if (value != null) {
+				return setter.apply(value, TimeUnit.SECONDS);
+			}
+			return cacheControl;
+		}
+
+	}
+
+
 }

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

@@ -73,6 +73,7 @@ import org.springframework.core.io.ResourceLoader;
 import org.springframework.format.Formatter;
 import org.springframework.format.FormatterRegistry;
 import org.springframework.format.datetime.DateFormatter;
+import org.springframework.http.CacheControl;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.MediaType;
 import org.springframework.http.converter.HttpMessageConverter;
@@ -133,6 +134,7 @@ import org.springframework.web.servlet.view.InternalResourceViewResolver;
  * @author Sébastien Deleuze
  * @author Eddú Meléndez
  * @author Stephane Nicoll
+ * @author Kristine Jetzke
  */
 @Configuration
 @ConditionalOnWebApplication(type = Type.SERVLET)
@@ -307,12 +309,14 @@ public class WebMvcAutoConfiguration {
 				return;
 			}
 			Duration cachePeriod = this.resourceProperties.getCachePeriod();
+			CacheControl cacheControl = this.resourceProperties.createCacheControl();
 			if (!registry.hasMappingForPattern("/webjars/**")) {
 				customizeResourceHandlerRegistration(
 						registry.addResourceHandler("/webjars/**")
 								.addResourceLocations(
 										"classpath:/META-INF/resources/webjars/")
-						.setCachePeriod(getSeconds(cachePeriod)));
+						.setCachePeriod(getSeconds(cachePeriod))
+						.setCacheControl(cacheControl));
 			}
 			String staticPathPattern = this.mvcProperties.getStaticPathPattern();
 			if (!registry.hasMappingForPattern(staticPathPattern)) {
@@ -320,7 +324,8 @@ public class WebMvcAutoConfiguration {
 						registry.addResourceHandler(staticPathPattern)
 								.addResourceLocations(getResourceLocations(
 										this.resourceProperties.getStaticLocations()))
-						.setCachePeriod(getSeconds(cachePeriod)));
+						.setCachePeriod(getSeconds(cachePeriod))
+						.setCacheControl(cacheControl));
 			}
 		}
 

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

@@ -18,6 +18,7 @@ package org.springframework.boot.autoconfigure.web;
 
 import org.junit.Test;
 
+import org.springframework.boot.autoconfigure.web.ResourceProperties.CacheControlProperties;
 import org.springframework.boot.testsupport.assertj.Matched;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -27,6 +28,7 @@ import static org.hamcrest.CoreMatchers.endsWith;
  * Tests for {@link ResourceProperties}.
  *
  * @author Stephane Nicoll
+ * @author Kristine Jetzke
  */
 public class ResourcePropertiesTests {
 
@@ -67,4 +69,54 @@ public class ResourcePropertiesTests {
 		assertThat(actual).containsExactly("/foo/", "/bar/", "/baz/");
 	}
 
+	@Test
+	public void cachePeriod() {
+		this.properties.setCachePeriod(5);
+		assertThat(this.properties.createCacheControl().getHeaderValue())
+				.isEqualTo("max-age=5");
+	}
+
+	@Test
+	public void cacheControlAllPropertiesSet() {
+		CacheControlProperties cacheControl = new CacheControlProperties();
+		cacheControl.setCachePrivate(true);
+		cacheControl.setCachePublic(true);
+		cacheControl.setMaxAge(4L);
+		cacheControl.setMustRevalidate(true);
+		cacheControl.setNoCache(true);
+		cacheControl.setNoCache(true);
+		cacheControl.setNoStore(true);
+		cacheControl.setNoTransform(true);
+		cacheControl.setProxyRevalidate(true);
+		cacheControl.setsMaxAge(5L);
+		cacheControl.setStaleIfError(6L);
+		cacheControl.setStaleWhileRevalidate(7L);
+		this.properties.setCacheControl(cacheControl);
+		assertThat(this.properties.createCacheControl().getHeaderValue()).isEqualTo(
+				"max-age=4, must-revalidate, no-transform, public, private, proxy-revalidate, s-maxage=5, stale-if-error=6, stale-while-revalidate=7");
+	}
+
+	@Test
+	public void cacheControlNoPropertiesSet() {
+		this.properties.setCacheControl(new CacheControlProperties());
+		assertThat(this.properties.createCacheControl().getHeaderValue()).isNull();
+	}
+
+	@Test
+	public void cacheControlAndCachePeriodSet() {
+		CacheControlProperties cacheControl = new CacheControlProperties();
+		cacheControl.setMaxAge(12L);
+		this.properties.setCacheControl(cacheControl);
+		this.properties.setCachePeriod(6);
+		assertThat(this.properties.createCacheControl().getHeaderValue())
+				.isEqualTo("max-age=6");
+	}
+
+	@Test
+	public void cacheControlAndCachePeriodBothNotSet() {
+		this.properties.setCacheControl(null);
+		this.properties.setCachePeriod(null);
+		assertThat(this.properties.createCacheControl()).isNull();
+	}
+
 }

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

@@ -16,11 +16,13 @@
 
 package org.springframework.boot.autoconfigure.web.servlet;
 
+import java.util.Collections;
 import java.util.Date;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
+import java.util.concurrent.TimeUnit;
 import java.util.function.Consumer;
 
 import javax.servlet.http.HttpServletRequest;
@@ -52,6 +54,7 @@ import org.springframework.core.convert.ConversionService;
 import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.Resource;
 import org.springframework.format.support.FormattingConversionService;
+import org.springframework.http.CacheControl;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.MediaType;
 import org.springframework.http.converter.HttpMessageConverter;
@@ -96,7 +99,9 @@ import org.springframework.web.servlet.resource.VersionStrategy;
 import org.springframework.web.servlet.view.AbstractView;
 import org.springframework.web.servlet.view.ContentNegotiatingViewResolver;
 
+
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.mockito.Mockito.mock;
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.forwardedUrl;
@@ -111,6 +116,7 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
  * @author Stephane Nicoll
  * @author Brian Clozel
  * @author Eddú Meléndez
+ * @author Kristine Jetzke
  */
 public class WebMvcAutoConfigurationTests {
 
@@ -797,6 +803,77 @@ public class WebMvcAutoConfigurationTests {
 				.run((context) -> assertThat(context).hasNotFailed());
 	}
 
+	@Test
+	public void cachePeriod() throws Exception {
+		this.contextRunner.withPropertyValues("spring.resources.cache-period:5")
+				.run((context) -> {
+					assertCachePeriod(context);
+				});
+	}
+
+	private void assertCachePeriod(AssertableWebApplicationContext context) {
+		Map<String, Object> handlerMap = getHandlerMap(context
+				.getBean("resourceHandlerMapping", HandlerMapping.class));
+		assertThat(handlerMap).hasSize(2);
+		for (Object handler : handlerMap.keySet()) {
+			if (handler instanceof ResourceHttpRequestHandler) {
+				assertThat(((ResourceHttpRequestHandler) handler)
+						.getCacheSeconds()).isEqualTo(-1);
+				assertThat(((ResourceHttpRequestHandler) handler)
+						.getCacheControl()).isEqualToComparingFieldByField(
+								CacheControl.maxAge(5, TimeUnit.SECONDS));
+			}
+		}
+	}
+
+	@Test
+	public void cacheControl() throws Exception {
+		this.contextRunner
+				.withPropertyValues("spring.resources.cache-control.max-age:5",
+						"spring.resources.cache-control.proxy-revalidate:true")
+				.run((context) -> {
+					assertCacheControl(context);
+				});
+	}
+
+	private void assertCacheControl(AssertableWebApplicationContext context) {
+		Map<String, Object> handlerMap = getHandlerMap(context
+				.getBean("resourceHandlerMapping", HandlerMapping.class));
+		assertThat(handlerMap).hasSize(2);
+		for (Object handler : handlerMap.keySet()) {
+			if (handler instanceof ResourceHttpRequestHandler) {
+				assertThat(((ResourceHttpRequestHandler) handler)
+						.getCacheSeconds()).isEqualTo(-1);
+				assertThat(((ResourceHttpRequestHandler) handler)
+						.getCacheControl()).isEqualToComparingFieldByField(
+								CacheControl.maxAge(5, TimeUnit.SECONDS)
+										.proxyRevalidate());
+			}
+		}
+	}
+
+	@Test
+	public void invalidCacheConfig() throws Exception {
+		assertThatThrownBy(() -> this.contextRunner
+				.withPropertyValues("spring.resources.cache-control.max-age:5",
+						"spring.resources.cache-period:6")
+				.run((context) -> getHandlerMap(
+						context.getBean("resourceHandlerMapping", HandlerMapping.class))))
+								.hasRootCauseInstanceOf(IllegalStateException.class)
+								.hasStackTraceContaining("Only one of cache-period or cache-control may be set");
+	}
+
+	@Test
+	public void invalidCacheControl() throws Exception {
+		assertThatThrownBy(() -> this.contextRunner
+				.withPropertyValues("spring.resources.cache-control.max-age:5",
+						"spring.resources.cache-control.no-cache:true")
+				.run((context) -> getHandlerMap(
+						context.getBean("resourceHandlerMapping", HandlerMapping.class))))
+								.hasRootCauseInstanceOf(IllegalStateException.class)
+								.hasStackTraceContaining("no-cache may not be set if max-age is set");
+	}
+
 	protected Map<String, List<Resource>> getFaviconMappingLocations(
 			ApplicationContext context) {
 		return getMappingLocations(
@@ -829,15 +906,21 @@ public class WebMvcAutoConfigurationTests {
 	@SuppressWarnings("unchecked")
 	protected Map<String, List<Resource>> getMappingLocations(HandlerMapping mapping) {
 		Map<String, List<Resource>> mappingLocations = new LinkedHashMap<>();
+		getHandlerMap(mapping).forEach((key, value) -> {
+			Object locations = ReflectionTestUtils.getField(value, "locations");
+			mappingLocations.put(key, (List<Resource>) locations);
+		});
+		return mappingLocations;
+	}
+
+	protected Map<String, Object> getHandlerMap(HandlerMapping mapping) {
 		if (mapping instanceof SimpleUrlHandlerMapping) {
-			((SimpleUrlHandlerMapping) mapping).getHandlerMap().forEach((key, value) -> {
-				Object locations = ReflectionTestUtils.getField(value, "locations");
-				mappingLocations.put(key, (List<Resource>) locations);
-			});
+			return ((SimpleUrlHandlerMapping) mapping).getHandlerMap();
 		}
-		return mappingLocations;
+		return Collections.emptyMap();
 	}
 
+
 	@Configuration
 	protected static class ViewConfig {