Improve caches endpoint format

This commit adds an intermediate "caches" element so that additional
cache manager attributes can be added in the future.

Closes gh-13079

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/endpoint/web/documentation/CachesEndpointDocumentationTests.java

@@ -68,9 +68,9 @@ public class CachesEndpointDocumentationTests extends MockMvcEndpointDocumentati
 				.andDo(MockMvcRestDocumentation.document("caches/all", responseFields(
 						fieldWithPath("cacheManagers")
 								.description("Cache managers keyed by id."),
-						fieldWithPath("cacheManagers.*").description(
+						fieldWithPath("cacheManagers.*.caches").description(
 								"Caches in the application context keyed by " + "name."))
-										.andWithPrefix("cacheManagers.*.*.",
+										.andWithPrefix("cacheManagers.*.caches.*.",
 												fieldWithPath("target").description(
 														"Fully qualified name of the native cache."))));
 	}

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/cache/CachesEndpoint.java

@@ -67,7 +67,10 @@ public class CachesEndpoint {
 			cacheManagerDescriptors.put(cacheName,
 					new CacheDescriptor(entry.getTarget()));
 		});
-		return new CachesReport(descriptors);
+		Map<String, CacheManagerDescriptor> cacheManagerDescriptors = new LinkedHashMap<>();
+		descriptors.forEach((name, entries) ->
+				cacheManagerDescriptors.put(name, new CacheManagerDescriptor(entries)));
+		return new CachesReport(cacheManagerDescriptors);
 	}
 
 	/**
@@ -160,18 +163,36 @@ public class CachesEndpoint {
 	 */
 	public static final class CachesReport {
 
-		private final Map<String, Map<String, CacheDescriptor>> cacheManagers;
+		private final Map<String, CacheManagerDescriptor> cacheManagers;
 
-		public CachesReport(Map<String, Map<String, CacheDescriptor>> cacheManagers) {
+		public CachesReport(Map<String, CacheManagerDescriptor> cacheManagers) {
 			this.cacheManagers = cacheManagers;
 		}
 
-		public Map<String, Map<String, CacheDescriptor>> getCacheManagers() {
+		public Map<String, CacheManagerDescriptor> getCacheManagers() {
 			return this.cacheManagers;
 		}
 
 	}
 
+	/**
+	 * Description of a {@link CacheManager}, primarily intended for serialization to
+	 * JSON.
+	 */
+	public static final class CacheManagerDescriptor {
+
+		private final Map<String, CacheDescriptor> caches;
+
+		public CacheManagerDescriptor(Map<String, CacheDescriptor> caches) {
+			this.caches = caches;
+		}
+
+		public Map<String, CacheDescriptor> getCaches() {
+			return this.caches;
+		}
+
+	}
+
 	/**
 	 * Basic description of a {@link Cache}, primarily intended for serialization to JSON.
 	 */

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/cache/CachesEndpointTests.java

@@ -26,8 +26,8 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
-import org.springframework.boot.actuate.cache.CachesEndpoint.CacheDescriptor;
 import org.springframework.boot.actuate.cache.CachesEndpoint.CacheEntry;
+import org.springframework.boot.actuate.cache.CachesEndpoint.CacheManagerDescriptor;
 import org.springframework.cache.Cache;
 import org.springframework.cache.CacheManager;
 import org.springframework.cache.concurrent.ConcurrentMapCacheManager;
@@ -53,14 +53,14 @@ public class CachesEndpointTests {
 	public void allCachesWithSingleCacheManager() {
 		CachesEndpoint endpoint = new CachesEndpoint(Collections.singletonMap("test",
 				new ConcurrentMapCacheManager("a", "b")));
-		Map<String, Map<String, CacheDescriptor>> allDescriptors = endpoint.caches()
+		Map<String, CacheManagerDescriptor> allDescriptors = endpoint.caches()
 				.getCacheManagers();
 		assertThat(allDescriptors).containsOnlyKeys("test");
-		Map<String, CacheDescriptor> descriptors = allDescriptors.get("test");
+		CacheManagerDescriptor descriptors = allDescriptors.get("test");
-		assertThat(descriptors).containsOnlyKeys("a", "b");
+		assertThat(descriptors.getCaches()).containsOnlyKeys("a", "b");
-		assertThat(descriptors.get("a").getTarget())
+		assertThat(descriptors.getCaches().get("a").getTarget())
 				.isEqualTo(ConcurrentHashMap.class.getName());
-		assertThat(descriptors.get("b").getTarget())
+		assertThat(descriptors.getCaches().get("b").getTarget())
 				.isEqualTo(ConcurrentHashMap.class.getName());
 	}
 
@@ -70,11 +70,11 @@ public class CachesEndpointTests {
 		cacheManagers.put("test", new ConcurrentMapCacheManager("a", "b"));
 		cacheManagers.put("another", new ConcurrentMapCacheManager("a", "c"));
 		CachesEndpoint endpoint = new CachesEndpoint(cacheManagers);
-		Map<String, Map<String, CacheDescriptor>> allDescriptors = endpoint.caches()
+		Map<String, CacheManagerDescriptor> allDescriptors = endpoint.caches()
 				.getCacheManagers();
 		assertThat(allDescriptors).containsOnlyKeys("test", "another");
-		assertThat(allDescriptors.get("test")).containsOnlyKeys("a", "b");
+		assertThat(allDescriptors.get("test").getCaches()).containsOnlyKeys("a", "b");
-		assertThat(allDescriptors.get("another")).containsOnlyKeys("a", "c");
+		assertThat(allDescriptors.get("another").getCaches()).containsOnlyKeys("a", "c");
 	}
 
 	@Test

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/cache/CachesEndpointWebIntegrationTests.java

@@ -49,13 +49,13 @@ public class CachesEndpointWebIntegrationTests {
 	@Test
 	public void allCaches() {
 		client.get().uri("/actuator/caches").exchange().expectStatus().isOk().expectBody()
-				.jsonPath("cacheManagers.one.a.target")
+				.jsonPath("cacheManagers.one.caches.a.target")
 				.isEqualTo(ConcurrentHashMap.class.getName())
-				.jsonPath("cacheManagers.one.b.target")
+				.jsonPath("cacheManagers.one.caches.b.target")
 				.isEqualTo(ConcurrentHashMap.class.getName())
-				.jsonPath("cacheManagers.two.a.target")
+				.jsonPath("cacheManagers.two.caches.a.target")
 				.isEqualTo(ConcurrentHashMap.class.getName())
-				.jsonPath("cacheManagers.two.c.target")
+				.jsonPath("cacheManagers.two.caches.c.target")
 				.isEqualTo(ConcurrentHashMap.class.getName());
 	}