Predict specific object type in EhCacheFactoryBean

Prior to this change, before a bean is created by EhCacheFactoryBean,
its #getObjectType would return only an Ehcache interface. This caused
unwanted wiring issues as described in the related JIRA issue.

This fix makes use of EhCacheFactoryBean's configuration to determine
the specific Ehcache object type even before it's created, such that
the container is provided with as much information as possible when
resolving dependencies. Nevertheless, users are advised to code to
the Ehcache interface.

Issue: SPR-7843

Author: sslavic

spring-context/src/main/java/org/springframework/cache/ehcache/EhCacheFactoryBean.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2011 the original author or authors.
+ * Copyright 2002-2012 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -31,6 +31,7 @@
 import net.sf.ehcache.constructs.blocking.UpdatingSelfPopulatingCache;
 import net.sf.ehcache.event.CacheEventListener;
 import net.sf.ehcache.store.MemoryStoreEvictionPolicy;
+
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
@@ -398,8 +399,27 @@ public Ehcache getObject() {
 		return this.cache;
 	}
 
+	/**
+	 * Predict the particular {@code Ehcache} implementation that will be returned from
+	 * {@link #getObject()} based on logic in {@link #createCache()} and
+	 * {@link #decorateCache(Ehcache)} as orchestrated by {@link #afterPropertiesSet()}.
+	 */
 	public Class<? extends Ehcache> getObjectType() {
-		return (this.cache != null ? this.cache.getClass() : Ehcache.class);
+		if (this.cache != null) {
+			return this.cache.getClass();
+		}
+		if (this.cacheEntryFactory != null) {
+			if (this.cacheEntryFactory instanceof UpdatingCacheEntryFactory) {
+				return UpdatingSelfPopulatingCache.class;
+			}
+			else {
+				return SelfPopulatingCache.class;
+			}
+		}
+		if (this.blocking) {
+			return BlockingCache.class;
+		}
+		return Cache.class;
 	}
 
 	public boolean isSingleton() {

spring-context/src/test/java/org/springframework/cache/ehcache/EhCacheSupportTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2012 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,6 +17,7 @@
 package org.springframework.cache.ehcache;
 
 import junit.framework.TestCase;
+
 import net.sf.ehcache.Cache;
 import net.sf.ehcache.CacheManager;
 import net.sf.ehcache.Ehcache;
@@ -82,7 +83,8 @@ private void doTestEhCacheFactoryBean(boolean useCacheManagerFb) throws Exceptio
 		EhCacheManagerFactoryBean cacheManagerFb = null;
 		try {
 			EhCacheFactoryBean cacheFb = new EhCacheFactoryBean();
-			assertEquals(Ehcache.class, cacheFb.getObjectType());
+			Class<? extends Ehcache> objectType = cacheFb.getObjectType();
+			assertTrue(Ehcache.class.isAssignableFrom(objectType));
 			assertTrue("Singleton property", cacheFb.isSingleton());
 			if (useCacheManagerFb) {
 				cacheManagerFb = new EhCacheManagerFactoryBean();
@@ -94,6 +96,8 @@ private void doTestEhCacheFactoryBean(boolean useCacheManagerFb) throws Exceptio
 			cacheFb.setCacheName("myCache1");
 			cacheFb.afterPropertiesSet();
 			cache = (Cache) cacheFb.getObject();
+			Class<? extends Ehcache> objectType2 = cacheFb.getObjectType();
+			assertSame(objectType, objectType2);
 			CacheConfiguration config = cache.getCacheConfiguration();
 			assertEquals("myCache1", cache.getName());
 			if (useCacheManagerFb){
@@ -166,6 +170,7 @@ public void testEhCacheFactoryBeanWithBlockingCache() throws Exception {
 			cacheFb.setCacheManager(cm);
 			cacheFb.setCacheName("myCache1");
 			cacheFb.setBlocking(true);
+			assertEquals(cacheFb.getObjectType(), BlockingCache.class);
 			cacheFb.afterPropertiesSet();
 			Ehcache myCache1 = cm.getEhcache("myCache1");
 			assertTrue(myCache1 instanceof BlockingCache);
@@ -188,6 +193,7 @@ public Object createEntry(Object key) throws Exception {
 					return key;
 				}
 			});
+			assertEquals(cacheFb.getObjectType(), SelfPopulatingCache.class);
 			cacheFb.afterPropertiesSet();
 			Ehcache myCache1 = cm.getEhcache("myCache1");
 			assertTrue(myCache1 instanceof SelfPopulatingCache);
@@ -213,6 +219,7 @@ public Object createEntry(Object key) throws Exception {
 				public void updateEntryValue(Object key, Object value) throws Exception {
 				}
 			});
+			assertEquals(cacheFb.getObjectType(), UpdatingSelfPopulatingCache.class);
 			cacheFb.afterPropertiesSet();
 			Ehcache myCache1 = cm.getEhcache("myCache1");
 			assertTrue(myCache1 instanceof UpdatingSelfPopulatingCache);