Cache Class — spring-boot Architecture

Source Code

core/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/WebProperties.java lines 355–618

		public static class Cache {

			private boolean customized;

			/**
			 * Cache period for the resources served by the resource handler. If a
			 * duration suffix is not specified, seconds will be used. Can be overridden
			 * by the 'spring.web.resources.cache.cachecontrol' properties.
			 */
			@DurationUnit(ChronoUnit.SECONDS)
			private @Nullable Duration period;

			/**
			 * Cache control HTTP headers, only allows valid directive combinations.
			 * Overrides the 'spring.web.resources.cache.period' property.
			 */
			private final Cachecontrol cachecontrol = new Cachecontrol();

			/**
			 * Whether we should use the "lastModified" metadata of the files in HTTP
			 * caching headers.
			 */
			private boolean useLastModified = true;

			public @Nullable Duration getPeriod() {
				return this.period;
			}

			public void setPeriod(@Nullable Duration period) {
				this.customized = true;
				this.period = period;
			}

			public Cachecontrol getCachecontrol() {
				return this.cachecontrol;
			}

			public boolean isUseLastModified() {
				return this.useLastModified;
			}

			public void setUseLastModified(boolean useLastModified) {
				this.useLastModified = useLastModified;
			}

			private boolean hasBeenCustomized() {
				return this.customized || getCachecontrol().hasBeenCustomized();
			}

			/**
			 * Cache Control HTTP header configuration.
			 */
			public static class Cachecontrol {

				private boolean customized;

				/**
				 * Maximum time the response should be cached, in seconds if no duration
				 * suffix is not specified.
				 */
				@DurationUnit(ChronoUnit.SECONDS)
				private @Nullable Duration maxAge;

				/**
				 * Indicate that the cached response can be reused only if re-validated
				 * with the server.
				 */
				private @Nullable Boolean noCache;

				/**
				 * Indicate to not cache the response in any case.
				 */
				private @Nullable Boolean noStore;

				/**
				 * Indicate that once it has become stale, a cache must not use the
				 * response without re-validating it with the server.
				 */
				private @Nullable Boolean mustRevalidate;

				/**
				 * Indicate intermediaries (caches and others) that they should not
				 * transform the response content.
				 */
				private @Nullable Boolean noTransform;

				/**
				 * Indicate that any cache may store the response.
				 */
				private @Nullable Boolean cachePublic;

				/**
				 * Indicate that the response message is intended for a single user and
				 * must not be stored by a shared cache.
				 */
				private @Nullable Boolean cachePrivate;

				/**
				 * Same meaning as the "must-revalidate" directive, except that it does
				 * not apply to private caches.
				 */
				private @Nullable Boolean proxyRevalidate;

				/**
				 * Maximum time the response can be served after it becomes stale, in
				 * seconds if no duration suffix is not specified.
				 */
				@DurationUnit(ChronoUnit.SECONDS)
				private @Nullable Duration staleWhileRevalidate;

				/**
				 * Maximum time the response may be used when errors are encountered, in
				 * seconds if no duration suffix is not specified.
				 */
				@DurationUnit(ChronoUnit.SECONDS)
				private @Nullable Duration staleIfError;

				/**
				 * Maximum time the response should be cached by shared caches, in seconds
				 * if no duration suffix is not specified.
				 */
				@DurationUnit(ChronoUnit.SECONDS)
				private @Nullable Duration sMaxAge;

				public @Nullable Duration getMaxAge() {
					return this.maxAge;
				}

				public void setMaxAge(@Nullable Duration maxAge) {
					this.customized = true;
					this.maxAge = maxAge;
				}

				public @Nullable Boolean getNoCache() {
					return this.noCache;
				}

				public void setNoCache(@Nullable Boolean noCache) {
					this.customized = true;
					this.noCache = noCache;
				}

				public @Nullable Boolean getNoStore() {
					return this.noStore;
				}

				public void setNoStore(@Nullable Boolean noStore) {
					this.customized = true;
					this.noStore = noStore;
				}

				public @Nullable Boolean getMustRevalidate() {
					return this.mustRevalidate;
				}

				public void setMustRevalidate(@Nullable Boolean mustRevalidate) {
					this.customized = true;
					this.mustRevalidate = mustRevalidate;
				}

				public @Nullable Boolean getNoTransform() {
					return this.noTransform;
				}

				public void setNoTransform(@Nullable Boolean noTransform) {
					this.customized = true;
					this.noTransform = noTransform;
				}

				public @Nullable Boolean getCachePublic() {
					return this.cachePublic;
				}

				public void setCachePublic(@Nullable Boolean cachePublic) {
					this.customized = true;
					this.cachePublic = cachePublic;
				}

				public @Nullable Boolean getCachePrivate() {
					return this.cachePrivate;
				}

				public void setCachePrivate(@Nullable Boolean cachePrivate) {
					this.customized = true;
					this.cachePrivate = cachePrivate;
				}

				public @Nullable Boolean getProxyRevalidate() {
					return this.proxyRevalidate;
				}

				public void setProxyRevalidate(@Nullable Boolean proxyRevalidate) {
					this.customized = true;
					this.proxyRevalidate = proxyRevalidate;
				}

				public @Nullable Duration getStaleWhileRevalidate() {
					return this.staleWhileRevalidate;
				}

				public void setStaleWhileRevalidate(@Nullable Duration staleWhileRevalidate) {
					this.customized = true;
					this.staleWhileRevalidate = staleWhileRevalidate;
				}

				public @Nullable Duration getStaleIfError() {
					return this.staleIfError;
				}

				public void setStaleIfError(@Nullable Duration staleIfError) {
					this.customized = true;
					this.staleIfError = staleIfError;
				}

				public @Nullable Duration getSMaxAge() {
					return this.sMaxAge;
				}

				public void setSMaxAge(@Nullable Duration sMaxAge) {
					this.customized = true;
					this.sMaxAge = sMaxAge;
				}

				public @Nullable CacheControl toHttpCacheControl() {
					PropertyMapper map = PropertyMapper.get();
					CacheControl control = createCacheControl();
					map.from(this::getMustRevalidate).whenTrue().toCall(control::mustRevalidate);
					map.from(this::getNoTransform).whenTrue().toCall(control::noTransform);
					map.from(this::getCachePublic).whenTrue().toCall(control::cachePublic);
					map.from(this::getCachePrivate).whenTrue().toCall(control::cachePrivate);
					map.from(this::getProxyRevalidate).whenTrue().toCall(control::proxyRevalidate);
					map.from(this::getStaleWhileRevalidate)
						.to((duration) -> control.staleWhileRevalidate(duration.getSeconds(), TimeUnit.SECONDS));
					map.from(this::getStaleIfError)
						.to((duration) -> control.staleIfError(duration.getSeconds(), TimeUnit.SECONDS));
					map.from(this::getSMaxAge)
						.to((duration) -> control.sMaxAge(duration.getSeconds(), TimeUnit.SECONDS));
					// check if cacheControl remained untouched
					if (control.getHeaderValue() == null) {
						return null;
					}
					return control;
				}

				private CacheControl createCacheControl() {
					if (Boolean.TRUE.equals(this.noStore)) {
						return CacheControl.noStore();
					}
					if (Boolean.TRUE.equals(this.noCache)) {
						return CacheControl.noCache();
					}
					if (this.maxAge != null) {
						return CacheControl.maxAge(this.maxAge.getSeconds(), TimeUnit.SECONDS);
					}
					return CacheControl.empty();
				}

				private boolean hasBeenCustomized() {
					return this.customized;
				}

			}

		}