DATAREDIS-375 - Avoid repeatedly decorating a cache.

Previously a transactional RedisCacheManager decorated a cache with the TransactionAwareCacheDecorator twice. We now make sure that a particular cache is only decorated once with a TransactionAwareCacheDecorator.

Original Pull Request: #128

src/test/java/org/springframework/data/redis/cache/RedisCacheManagerTransactionalUnitTests.java

@@ -0,0 +1,126 @@
+/*
+ * Copyright 2015 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.redis.cache;
+
+import static org.junit.Assert.*;
+import static org.mockito.Mockito.*;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.util.Arrays;
+
+import javax.sql.DataSource;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.DirectFieldAccessor;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.cache.Cache;
+import org.springframework.cache.CacheManager;
+import org.springframework.cache.annotation.EnableCaching;
+import org.springframework.cache.transaction.TransactionAwareCacheDecorator;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.redis.connection.RedisConnection;
+import org.springframework.data.redis.connection.RedisConnectionFactory;
+import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.data.redis.test.util.RelaxedJUnit4ClassRunner;
+import org.springframework.jdbc.datasource.DataSourceTransactionManager;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.transaction.TransactionConfiguration;
+import org.springframework.transaction.PlatformTransactionManager;
+import org.springframework.transaction.annotation.Transactional;
+
+/**
+ * @author Thomas Darimont
+ */
+@RunWith(RelaxedJUnit4ClassRunner.class)
+@ContextConfiguration
+@Transactional
+@TransactionConfiguration(transactionManager = "transactionManager")
+public class RedisCacheManagerTransactionalUnitTests {
+
+	@Autowired protected CacheManager cacheManager;
+
+	private final static String cacheName = "cache-name";
+
+	@Configuration
+	@EnableCaching
+	public static class Config {
+
+		@Bean
+		public PlatformTransactionManager transactionManager() throws SQLException {
+
+			DataSourceTransactionManager txmgr = new DataSourceTransactionManager();
+			txmgr.setDataSource(dataSource());
+			txmgr.afterPropertiesSet();
+
+			return txmgr;
+		}
+
+		@Bean
+		public DataSource dataSource() throws SQLException {
+
+			DataSource dataSourceMock = mock(DataSource.class);
+			when(dataSourceMock.getConnection()).thenReturn(mock(Connection.class));
+
+			return dataSourceMock;
+		}
+
+		@Bean
+		public CacheManager cacheManager() {
+
+			RedisCacheManager cacheManager = new RedisCacheManager(redisTemplate());
+			cacheManager.setTransactionAware(true);
+			cacheManager.setCacheNames(Arrays.asList(cacheName));
+			return cacheManager;
+		}
+
+		@SuppressWarnings({ "rawtypes" })
+		@Bean
+		public RedisTemplate redisTemplate() {
+
+			RedisConnection connectionMock = mock(RedisConnection.class);
+			RedisConnectionFactory factoryMock = mock(RedisConnectionFactory.class);
+
+			when(factoryMock.getConnection()).thenReturn(connectionMock);
+
+			RedisTemplate template = new RedisTemplate();
+			template.setConnectionFactory(factoryMock);
+
+			return template;
+		}
+	}
+
+	/**
+	 * @see DATAREDIS-375
+	 */
+	@Test
+	public void testCacheIsNotDecoratedTwiceWithTransactionAwareCacheDecorator() {
+
+		Cache cache = cacheManager.getCache(cacheName);
+
+		// the cache must be decorated with the TransactionAwareCacheDecorator
+		assertTrue(cache instanceof TransactionAwareCacheDecorator);
+		TransactionAwareCacheDecorator transactionalCache = (TransactionAwareCacheDecorator) cache;
+
+		// get the target cache via reflection
+		Object targetCache = new DirectFieldAccessor(transactionalCache).getPropertyValue("targetCache");
+
+		// the target cache must be an instance of RedisCache and not TransactionAwareCacheDecorator
+		assertTrue(targetCache instanceof RedisCache);
+	}
+}