SpringCacheAnnotationParser properly accepts empty @caching annotation

Issue: SPR-14162

Author: jhoeller

spring-context/src/main/java/org/springframework/cache/annotation/SpringCacheAnnotationParser.java

@@ -87,7 +87,10 @@ protected Collection<CacheOperation> parseCacheAnnotations(DefaultCacheConfig ca
 		if (!cachings.isEmpty()) {
 			ops = lazyInit(ops);
 			for (Caching caching : cachings) {
-				ops.addAll(parseCachingAnnotation(ae, cachingConfig, caching));
+				Collection<CacheOperation> cachingOps = parseCachingAnnotation(ae, cachingConfig, caching);
+				if (cachingOps != null) {
+					ops.addAll(cachingOps);
+				}
 			}
 		}
 

spring-context/src/test/java/org/springframework/cache/annotation/AnnotationCacheOperationSourceTests.java

@@ -49,7 +49,7 @@ public class AnnotationCacheOperationSourceTests {
 	@Rule
 	public final ExpectedException exception = ExpectedException.none();
 
-	private AnnotationCacheOperationSource source = new AnnotationCacheOperationSource();
+	private final AnnotationCacheOperationSource source = new AnnotationCacheOperationSource();
 
 
 	private Collection<CacheOperation> getOps(Class<?> target, String name, int expectedNumberOfOperations) {
@@ -85,6 +85,11 @@ public void caching() throws Exception {
 		assertTrue(it.next() instanceof CacheEvictOperation);
 	}
 
+	@Test
+	public void emptyCaching() throws Exception {
+		Collection<CacheOperation> ops = getOps(AnnotatedClass.class, "emptyCaching", 0);
+	}
+
 	@Test
 	public void singularStereotype() throws Exception {
 		Collection<CacheOperation> ops = getOps(AnnotatedClass.class, "singleStereotype", 1);
@@ -272,17 +277,20 @@ public void partialClassLevelWithNoCustomization() {
 		assertSharedConfig(cacheOperation, "classKeyGenerator", "classCacheManager", "", "classCacheName");
 	}
 
+
 	private void assertSharedConfig(CacheOperation actual, String keyGenerator, String cacheManager,
-									String cacheResolver, String... cacheNames) {
+			String cacheResolver, String... cacheNames) {
+
 		assertEquals("Wrong key manager",  keyGenerator, actual.getKeyGenerator());
 		assertEquals("Wrong cache manager", cacheManager, actual.getCacheManager());
 		assertEquals("Wrong cache resolver", cacheResolver, actual.getCacheResolver());
 		assertEquals("Wrong number of cache names", cacheNames.length, actual.getCacheNames().size());
 		Arrays.stream(cacheNames).forEach(
-			cacheName -> assertTrue("Cache '" + cacheName + "' not found in " + actual.getCacheNames(),
-				actual.getCacheNames().contains(cacheName)));
+				cacheName -> assertTrue("Cache '" + cacheName + "' not found in " + actual.getCacheNames(),
+						actual.getCacheNames().contains(cacheName)));
 	}
 
+
 	private static class AnnotatedClass {
 
 		@Cacheable("test")
@@ -298,6 +306,10 @@ public void multiple() {
 		public void caching() {
 		}
 
+		@Caching
+		public void emptyCaching() {
+		}
+
 		@Cacheable(cacheNames = "test", keyGenerator = "custom")
 		public void customKeyGenerator() {
 		}
@@ -361,6 +373,7 @@ public void noCacheNameSpecified() {
 		}
 	}
 
+
 	@CacheConfig(cacheNames = "classCacheName",
 			keyGenerator = "classKeyGenerator",
 			cacheManager = "classCacheManager", cacheResolver = "classCacheResolver")
@@ -383,6 +396,7 @@ public void methodLevelCacheResolver() {
 		}
 	}
 
+
 	@CacheConfigFoo
 	private static class AnnotatedClassWithCustomDefault {
 
@@ -391,6 +405,7 @@ public void methodLevelCacheName() {
 		}
 	}
 
+
 	@CacheConfig(cacheNames = "classCacheName",
 			keyGenerator = "classKeyGenerator",
 			cacheManager = "classCacheManager")
@@ -409,6 +424,7 @@ public void noCustomization() {
 		}
 	}
 
+
 	@CacheConfigFoo
 	@CacheConfig(cacheNames = "myCache") // multiple sources
 	private static class MultipleCacheConfig {
@@ -418,48 +434,58 @@ public void multipleCacheConfig() {
 		}
 	}
 
+
 	@Retention(RetentionPolicy.RUNTIME)
 	@Target(ElementType.METHOD)
 	@Cacheable("foo")
 	public @interface CacheableFoo {
 	}
 
+
 	@Retention(RetentionPolicy.RUNTIME)
 	@Target(ElementType.METHOD)
 	@Cacheable(cacheNames = "foo", keyGenerator = "custom")
 	public @interface CacheableFooCustomKeyGenerator {
 	}
 
+
 	@Retention(RetentionPolicy.RUNTIME)
 	@Target(ElementType.METHOD)
 	@Cacheable(cacheNames = "foo", cacheManager = "custom")
 	public @interface CacheableFooCustomCacheManager {
 	}
 
+
 	@Retention(RetentionPolicy.RUNTIME)
 	@Target(ElementType.METHOD)
 	@Cacheable(cacheNames = "foo", cacheResolver = "custom")
 	public @interface CacheableFooCustomCacheResolver {
 	}
 
+
 	@Retention(RetentionPolicy.RUNTIME)
 	@Target(ElementType.METHOD)
 	@CacheEvict("foo")
 	public @interface EvictFoo {
 	}
 
+
 	@Retention(RetentionPolicy.RUNTIME)
 	@Target(ElementType.METHOD)
 	@CacheEvict("bar")
 	public @interface EvictBar {
 	}
 
+
 	@Retention(RetentionPolicy.RUNTIME)
 	@Target(ElementType.TYPE)
-	@CacheConfig(keyGenerator = "classKeyGenerator", cacheManager = "classCacheManager", cacheResolver = "classCacheResolver")
+	@CacheConfig(keyGenerator = "classKeyGenerator",
+			cacheManager = "classCacheManager",
+			cacheResolver = "classCacheResolver")
 	public @interface CacheConfigFoo {
 	}
 
+
 	@Retention(RetentionPolicy.RUNTIME)
 	@Target({ ElementType.METHOD, ElementType.TYPE })
 	@Cacheable(cacheNames = "shadowed cache name", key = "shadowed key")
@@ -475,6 +501,7 @@ public void multipleCacheConfig() {
 		String key() default "";
 	}
 
+
 	@Retention(RetentionPolicy.RUNTIME)
 	@Target({ ElementType.METHOD, ElementType.TYPE })
 	@CacheEvict(cacheNames = "shadowed cache name", key = "shadowed key")
@@ -490,4 +517,4 @@ public void multipleCacheConfig() {
 		String key() default "";
 	}
 
-}
+}