Expose caching-specific infrastructure

Expose the underlying cache infrastructure bean if Boot auto-configures
it. This is the case for ehCache, hazelcast and JCache. This change has
two side effects:

1. It is now possible to customize the underlying cache infrastructure
and let Boot only wrap it in the Spring's CacheManager abstraction. No
customizations are applied if the caching-specific service is customized
2. Such infrastructure is disposed when the application terminates as
it is now defined as `@Bean` and both `close()` and `shutdown()` methods
are invoked if present on the target type.

While the latter can be troublesome, we feel that a particular cache
instance is not meant to be shared and must be disposed when the
application terminates.

Closes gh-2848

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/cache/EhCacheCacheConfiguration.java

@@ -17,11 +17,11 @@
 package org.springframework.boot.autoconfigure.cache;
 
 import net.sf.ehcache.Cache;
+import net.sf.ehcache.CacheManager;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
-import org.springframework.cache.CacheManager;
 import org.springframework.cache.ehcache.EhCacheCacheManager;
 import org.springframework.cache.ehcache.EhCacheManagerUtils;
 import org.springframework.context.annotation.Bean;
@@ -34,11 +34,12 @@ import org.springframework.core.io.Resource;
  * a default configuration file exists.
  *
  * @author Eddú Meléndez
+ * @author Stephane Nicoll
  * @since 1.3.0
  */
 @Configuration
 @ConditionalOnClass({ Cache.class, EhCacheCacheManager.class })
-@ConditionalOnMissingBean(CacheManager.class)
+@ConditionalOnMissingBean(org.springframework.cache.CacheManager.class)
 @Conditional({ CacheCondition.class,
 		EhCacheCacheConfiguration.ConfigAvailableCondition.class })
 class EhCacheCacheConfiguration {
@@ -47,13 +48,18 @@ class EhCacheCacheConfiguration {
 	private CacheProperties properties;
 
 	@Bean
-	public EhCacheCacheManager cacheManager() {
+	public EhCacheCacheManager cacheManager(CacheManager ehCacheCacheManager) {
+		return new EhCacheCacheManager(ehCacheCacheManager);
+	}
+
+	@Bean
+	@ConditionalOnMissingBean
+	public CacheManager ehCacheCacheManager() {
 		Resource location = this.properties.resolveConfigLocation();
 		if (location != null) {
-			return new EhCacheCacheManager(
-					EhCacheManagerUtils.buildCacheManager(location));
+			return EhCacheManagerUtils.buildCacheManager(location);
 		}
-		return new EhCacheCacheManager(EhCacheManagerUtils.buildCacheManager());
+		return EhCacheManagerUtils.buildCacheManager();
 	}
 
 	/**

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/cache/HazelcastCacheConfiguration.java

@@ -57,11 +57,13 @@ class HazelcastCacheConfiguration {
 	private CacheProperties cacheProperties;
 
 	@Bean
-	public HazelcastCacheManager cacheManager() throws IOException {
-		return new HazelcastCacheManager(createHazelcastInstance());
+	public HazelcastCacheManager cacheManager(HazelcastInstance hazelcastInstance) {
+		return new HazelcastCacheManager(hazelcastInstance);
 	}
 
-	private HazelcastInstance createHazelcastInstance() throws IOException {
+	@Bean
+	@ConditionalOnMissingBean
+	public HazelcastInstance hazelcastInstance() throws IOException {
 		Resource location = this.cacheProperties.resolveConfigLocation();
 		if (location != null) {
 			Config cfg = new XmlConfigBuilder(location.getURL()).build();

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/cache/JCacheCacheConfiguration.java

@@ -27,9 +27,11 @@ import javax.cache.configuration.MutableConfiguration;
 import javax.cache.spi.CachingProvider;
 
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.condition.AnyNestedCondition;
 import org.springframework.boot.autoconfigure.condition.ConditionOutcome;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnSingleCandidate;
 import org.springframework.boot.autoconfigure.condition.SpringBootCondition;
 import org.springframework.boot.bind.RelaxedPropertyResolver;
 import org.springframework.cache.jcache.JCacheCacheManager;
@@ -68,19 +70,13 @@ class JCacheCacheConfiguration {
 	private List<JCacheManagerCustomizer> cacheManagerCustomizers;
 
 	@Bean
-	public JCacheCacheManager cacheManager() throws IOException {
-		CacheManager cacheManager = createCacheManager();
-		List<String> cacheNames = this.cacheProperties.getCacheNames();
-		if (!CollectionUtils.isEmpty(cacheNames)) {
-			for (String cacheName : cacheNames) {
-				cacheManager.createCache(cacheName, getDefaultCacheConfiguration());
-			}
-		}
-		customize(cacheManager);
-		return new JCacheCacheManager(cacheManager);
+	public JCacheCacheManager cacheManager(CacheManager jCacheCacheManager) {
+		return new JCacheCacheManager(jCacheCacheManager);
 	}
 
-	private CacheManager createCacheManager() throws IOException {
+	@Bean
+	@ConditionalOnMissingBean
+	public CacheManager jCacheCacheManager() throws IOException {
 		CachingProvider cachingProvider = getCachingProvider(this.cacheProperties
 				.getJcache().getProvider());
 		Resource configLocation = this.cacheProperties.resolveConfigLocation();
@@ -89,7 +85,15 @@ class JCacheCacheConfiguration {
 					cachingProvider.getDefaultClassLoader(),
 					createCacheManagerProperties(configLocation));
 		}
-		return cachingProvider.getCacheManager();
+		CacheManager jCacheCacheManager = cachingProvider.getCacheManager();
+		List<String> cacheNames = this.cacheProperties.getCacheNames();
+		if (!CollectionUtils.isEmpty(cacheNames)) {
+			for (String cacheName : cacheNames) {
+				jCacheCacheManager.createCache(cacheName, getDefaultCacheConfiguration());
+			}
+		}
+		customize(jCacheCacheManager);
+		return jCacheCacheManager;
 	}
 
 	private CachingProvider getCachingProvider(String cachingProviderFqn) {
@@ -125,12 +129,32 @@ class JCacheCacheConfiguration {
 	}
 
 	/**
-	 * Determines if JCache is available. This either kick in if a default
+	 * Determine if JCache is available. This either kick in if a provider is available
+	 * as defined per {@link JCacheProviderAvailableCondition} or if a {@link CacheManager}
+	 * has already been defined.
+	 */
+	@Order(Ordered.LOWEST_PRECEDENCE)
+	static class JCacheAvailableCondition extends AnyNestedCondition {
+
+		public JCacheAvailableCondition() {
+			super(ConfigurationPhase.REGISTER_BEAN);
+		}
+
+		@Conditional(JCacheProviderAvailableCondition.class)
+		static class JCacheProvider {}
+
+		@ConditionalOnSingleCandidate(CacheManager.class)
+		static class CustomJCacheCacheManager {}
+
+	}
+
+	/**
+	 * Determine if a JCache provider is available. This either kick in if a default
 	 * {@link CachingProvider} has been found or if the property referring to the provider
 	 * to use has been set.
 	 */
 	@Order(Ordered.LOWEST_PRECEDENCE)
-	static class JCacheAvailableCondition extends SpringBootCondition {
+	static class JCacheProviderAvailableCondition extends SpringBootCondition {
 
 		@Override
 		public ConditionOutcome getMatchOutcome(ConditionContext context,

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/cache/CacheAutoConfigurationTests.java

@@ -19,16 +19,22 @@ package org.springframework.boot.autoconfigure.cache;
 import java.io.IOException;
 import java.util.Collection;
 import java.util.Collections;
-
 import javax.cache.configuration.CompleteConfiguration;
 import javax.cache.configuration.MutableConfiguration;
 import javax.cache.expiry.CreatedExpiryPolicy;
 import javax.cache.expiry.Duration;
 
+import com.google.common.cache.CacheBuilder;
+import com.hazelcast.cache.HazelcastCachingProvider;
+import com.hazelcast.core.HazelcastInstance;
+import com.hazelcast.spring.cache.HazelcastCacheManager;
+import net.sf.ehcache.Status;
 import org.junit.After;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
+
+import org.springframework.beans.DirectFieldAccessor;
 import org.springframework.beans.factory.BeanCreationException;
 import org.springframework.beans.factory.NoSuchBeanDefinitionException;
 import org.springframework.boot.autoconfigure.cache.support.MockCachingProvider;
@@ -56,10 +62,6 @@ import org.springframework.core.io.Resource;
 import org.springframework.data.redis.cache.RedisCacheManager;
 import org.springframework.data.redis.core.RedisTemplate;
 
-import com.google.common.cache.CacheBuilder;
-import com.hazelcast.cache.HazelcastCachingProvider;
-import com.hazelcast.spring.cache.HazelcastCacheManager;
-
 import static org.hamcrest.CoreMatchers.equalTo;
 import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.hamcrest.Matchers.contains;
@@ -70,6 +72,7 @@ import static org.hamcrest.core.Is.is;
 import static org.junit.Assert.assertThat;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
 /**
  * Tests for {@link CacheAutoConfiguration}.
@@ -213,6 +216,8 @@ public class CacheAutoConfigurationTests {
 				"spring.cache.jcache.provider=" + cachingProviderFqn);
 		JCacheCacheManager cacheManager = validateCacheManager(JCacheCacheManager.class);
 		assertThat(cacheManager.getCacheNames(), is(empty()));
+		assertThat(this.context.getBean(javax.cache.CacheManager.class),
+				is(cacheManager.getCacheManager()));
 	}
 
 	@Test
@@ -244,6 +249,13 @@ public class CacheAutoConfigurationTests {
 				defaultCacheConfiguration);
 	}
 
+	@Test
+	public void jCacheCacheWithExistingJCacheManager() {
+		load(JCacheCustomCacheManager.class, "spring.cache.type=jcache");
+		JCacheCacheManager cacheManager = validateCacheManager(JCacheCacheManager.class);
+		assertThat(cacheManager.getCacheManager(), is(this.context.getBean("customJCacheCacheManager")));
+	}
+
 	@Test
 	public void jCacheCacheWithUnknownProvider() {
 		String wrongCachingProviderFqn = "org.acme.FooBar";
@@ -280,36 +292,29 @@ public class CacheAutoConfigurationTests {
 	@Test
 	public void ehCacheCacheWithCaches() {
 		load(DefaultCacheConfiguration.class, "spring.cache.type=ehcache");
-		EhCacheCacheManager cacheManager = null;
-		try {
-			cacheManager = validateCacheManager(EhCacheCacheManager.class);
-			assertThat(cacheManager.getCacheNames(),
-					containsInAnyOrder("cacheTest1", "cacheTest2"));
-			assertThat(cacheManager.getCacheNames(), hasSize(2));
-		}
-		finally {
-			if (cacheManager != null) {
-				cacheManager.getCacheManager().shutdown();
-			}
-		}
+		EhCacheCacheManager cacheManager = validateCacheManager(EhCacheCacheManager.class);
+		assertThat(cacheManager.getCacheNames(),
+				containsInAnyOrder("cacheTest1", "cacheTest2"));
+		assertThat(cacheManager.getCacheNames(), hasSize(2));
+		assertThat(this.context.getBean(net.sf.ehcache.CacheManager.class),
+				is(cacheManager.getCacheManager()));
 	}
 
 	@Test
 	public void ehCacheCacheWithConfig() {
 		load(DefaultCacheConfiguration.class, "spring.cache.type=ehcache",
 				"spring.cache.config=cache/ehcache-override.xml");
-		EhCacheCacheManager cacheManager = null;
-		try {
-			cacheManager = validateCacheManager(EhCacheCacheManager.class);
-			assertThat(cacheManager.getCacheNames(),
-					containsInAnyOrder("cacheOverrideTest1", "cacheOverrideTest2"));
-			assertThat(cacheManager.getCacheNames(), hasSize(2));
-		}
-		finally {
-			if (cacheManager != null) {
-				cacheManager.getCacheManager().shutdown();
-			}
-		}
+		EhCacheCacheManager cacheManager = validateCacheManager(EhCacheCacheManager.class);
+		assertThat(cacheManager.getCacheNames(),
+				containsInAnyOrder("cacheOverrideTest1", "cacheOverrideTest2"));
+		assertThat(cacheManager.getCacheNames(), hasSize(2));
+	}
+
+	@Test
+	public void ehCacheCacheWithExistingCacheManager() {
+		load(EhCacheCustomCacheManager.class, "spring.cache.type=ehcache");
+		EhCacheCacheManager cacheManager = validateCacheManager(EhCacheCacheManager.class);
+		assertThat(cacheManager.getCacheManager(), is(this.context.getBean("customEhCacheCacheManager")));
 	}
 
 	@Test
@@ -320,6 +325,8 @@ public class CacheAutoConfigurationTests {
 		cacheManager.getCache("defaultCache");
 		assertThat(cacheManager.getCacheNames(), containsInAnyOrder("defaultCache"));
 		assertThat(cacheManager.getCacheNames(), hasSize(1));
+		assertThat(this.context.getBean(HazelcastInstance.class),
+				is(new DirectFieldAccessor(cacheManager).getPropertyValue("hazelcastInstance")));
 	}
 
 	@Test
@@ -340,65 +347,49 @@ public class CacheAutoConfigurationTests {
 				"spring.cache.config=foo/bar/unknown.xml");
 	}
 
+	@Test
+	public void hazelcastCacheWithExistingHazelcastInstance() {
+		load(HazelcastCustomHazelcastInstance.class, "spring.cache.type=hazelcast");
+		HazelcastCacheManager cacheManager = validateCacheManager(HazelcastCacheManager.class);
+		assertThat(new DirectFieldAccessor(cacheManager).getPropertyValue("hazelcastInstance"),
+				is(this.context.getBean("customHazelcastInstance")));
+	}
+
 	@Test
 	public void hazelcastAsJCacheWithCaches() {
 		String cachingProviderFqn = HazelcastCachingProvider.class.getName();
-		JCacheCacheManager cacheManager = null;
-		try {
-			load(DefaultCacheConfiguration.class, "spring.cache.type=jcache",
-					"spring.cache.jcache.provider=" + cachingProviderFqn,
-					"spring.cache.cacheNames[0]=foo", "spring.cache.cacheNames[1]=bar");
-			cacheManager = validateCacheManager(JCacheCacheManager.class);
-			assertThat(cacheManager.getCacheNames(), containsInAnyOrder("foo", "bar"));
-			assertThat(cacheManager.getCacheNames(), hasSize(2));
-		}
-		finally {
-			if (cacheManager != null) {
-				cacheManager.getCacheManager().close();
-			}
-		}
+		load(DefaultCacheConfiguration.class, "spring.cache.type=jcache",
+				"spring.cache.jcache.provider=" + cachingProviderFqn,
+				"spring.cache.cacheNames[0]=foo", "spring.cache.cacheNames[1]=bar");
+		JCacheCacheManager cacheManager = validateCacheManager(JCacheCacheManager.class);
+		assertThat(cacheManager.getCacheNames(), containsInAnyOrder("foo", "bar"));
+		assertThat(cacheManager.getCacheNames(), hasSize(2));
 	}
 
 	@Test
 	public void hazelcastAsJCacheWithConfig() throws IOException {
 		String cachingProviderFqn = HazelcastCachingProvider.class.getName();
 		String configLocation = "org/springframework/boot/autoconfigure/cache/hazelcast-specific.xml";
-		JCacheCacheManager cacheManager = null;
-		try {
-			load(DefaultCacheConfiguration.class, "spring.cache.type=jcache",
-					"spring.cache.jcache.provider=" + cachingProviderFqn,
-					"spring.cache.config=" + configLocation);
-			cacheManager = validateCacheManager(JCacheCacheManager.class);
-
-			Resource configResource = new ClassPathResource(configLocation);
-			assertThat(cacheManager.getCacheManager().getURI(),
-					is(configResource.getURI()));
-		}
-		finally {
-			if (cacheManager != null) {
-				cacheManager.getCacheManager().close();
-			}
-		}
+		load(DefaultCacheConfiguration.class, "spring.cache.type=jcache",
+				"spring.cache.jcache.provider=" + cachingProviderFqn,
+				"spring.cache.config=" + configLocation);
+		JCacheCacheManager cacheManager = validateCacheManager(JCacheCacheManager.class);
+
+		Resource configResource = new ClassPathResource(configLocation);
+		assertThat(cacheManager.getCacheManager().getURI(),
+				is(configResource.getURI()));
 	}
 
 	@Test
 	public void jCacheCacheWithCachesAndCustomizer() {
 		String cachingProviderFqn = HazelcastCachingProvider.class.getName();
-		JCacheCacheManager cacheManager = null;
-		try {
-			load(JCacheWithCustomizerConfiguration.class, "spring.cache.type=jcache",
-					"spring.cache.jcache.provider=" + cachingProviderFqn,
-					"spring.cache.cacheNames[0]=foo", "spring.cache.cacheNames[1]=bar");
-			cacheManager = validateCacheManager(JCacheCacheManager.class);
-			assertThat(cacheManager.getCacheNames(), containsInAnyOrder("foo", "custom1")); // see
-																							// customizer
-			assertThat(cacheManager.getCacheNames(), hasSize(2));
-		}
-		finally {
-			if (cacheManager != null) {
-				cacheManager.getCacheManager().close();
-			}
-		}
+		load(JCacheWithCustomizerConfiguration.class, "spring.cache.type=jcache",
+				"spring.cache.jcache.provider=" + cachingProviderFqn,
+				"spring.cache.cacheNames[0]=foo", "spring.cache.cacheNames[1]=bar");
+		JCacheCacheManager cacheManager = validateCacheManager(JCacheCacheManager.class);
+		assertThat(cacheManager.getCacheNames(), containsInAnyOrder("foo", "custom1")); // see
+		// customizer
+		assertThat(cacheManager.getCacheNames(), hasSize(2));
 	}
 
 	@Test
@@ -505,6 +496,19 @@ public class CacheAutoConfigurationTests {
 
 	}
 
+	@Configuration
+	@EnableCaching
+	static class JCacheCustomCacheManager {
+
+		@Bean
+		public javax.cache.CacheManager customJCacheCacheManager() {
+			javax.cache.CacheManager cacheManager = mock(javax.cache.CacheManager.class);
+			when(cacheManager.getCacheNames()).thenReturn(Collections.<String>emptyList());
+			return cacheManager;
+		}
+
+	}
+
 	@Configuration
 	@EnableCaching
 	static class JCacheWithCustomizerConfiguration {
@@ -526,6 +530,31 @@ public class CacheAutoConfigurationTests {
 
 	}
 
+	@Configuration
+	@EnableCaching
+	static class EhCacheCustomCacheManager {
+
+		@Bean
+		public net.sf.ehcache.CacheManager customEhCacheCacheManager() {
+			net.sf.ehcache.CacheManager cacheManager = mock(net.sf.ehcache.CacheManager.class);
+			when(cacheManager.getStatus()).thenReturn(Status.STATUS_ALIVE);
+			when(cacheManager.getCacheNames()).thenReturn(new String[0]);
+			return cacheManager;
+		}
+
+	}
+
+	@Configuration
+	@EnableCaching
+	static class HazelcastCustomHazelcastInstance {
+
+		@Bean
+		public HazelcastInstance customHazelcastInstance() {
+			return mock(HazelcastInstance.class);
+		}
+
+	}
+
 	@Configuration
 	@Import({ GenericCacheConfiguration.class, RedisCacheConfiguration.class })
 	static class CustomCacheManagerConfiguration {