Improve cache auto-configuration for Redis

Expose key prefix, TTL and null value settings for spring-data-redis'
RedisCacheConfiguration in Spring .properties/yml configuration files.

Example:

spring.cache.redis.ttl=PT15M
spring.cache.redis.keyPrefix=foo
spring.cache.redis.useKeyPrefix=false
spring.cache.redis.cacheNullValues=false

See gh-10795

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

@@ -16,6 +16,7 @@
 
 package org.springframework.boot.autoconfigure.cache;
 
+import java.time.Duration;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
@@ -29,6 +30,7 @@ import org.springframework.util.Assert;
  *
  * @author Stephane Nicoll
  * @author Eddú Meléndez
+ * @author Ryon Day
  * @since 1.3.0
  */
 @ConfigurationProperties(prefix = "spring.cache")
@@ -55,6 +57,8 @@ public class CacheProperties {
 
 	private final JCache jcache = new JCache();
 
+	private final Redis redis = new Redis();
+
 	public CacheType getType() {
 		return this.type;
 	}
@@ -91,6 +95,10 @@ public class CacheProperties {
 		return this.jcache;
 	}
 
+	public Redis getRedis() {
+		return this.redis;
+	}
+
 	/**
 	 * Resolve the config location if set.
 	 * @param config the config resource
@@ -233,4 +241,69 @@ public class CacheProperties {
 
 	}
 
+	/**
+	 * Redis-specific cache properties. Properties set will be used as the defaults for
+	 * all Redis caches.
+	 */
+	public static class Redis {
+
+		/**
+		 * Specifies the TTL (ultimately converted to seconds) for keys written to Redis.
+		 * By default, entries do not expire, and a value of {@link Duration#ZERO} disables the TTL.
+		 */
+		private Duration ttl = Duration.ZERO;
+
+		/**
+		 * Whether to allow caching of {@literal null} values.
+		 */
+		private boolean cacheNullValues = true;
+
+		/**
+		 * Specifies an override for the default Redis key prefix. A value of {@literal null} results
+		 * in usage of the default key prefix.
+		 */
+		private String keyPrefix;
+
+		/**
+		 * Whether to use the key prefix when writing to Redis.
+		 */
+		private boolean useKeyPrefix = true;
+
+		public Duration getTtl() {
+			return this.ttl;
+		}
+
+		public Redis setTtl(Duration ttl) {
+			this.ttl = ttl;
+			return this;
+		}
+
+		public boolean isCacheNullValues() {
+			return this.cacheNullValues;
+		}
+
+		public Redis setCacheNullValues(boolean cacheNullValues) {
+			this.cacheNullValues = cacheNullValues;
+			return this;
+		}
+
+		public String getKeyPrefix() {
+			return this.keyPrefix;
+		}
+
+		public Redis setKeyPrefix(String keyPrefix) {
+			this.keyPrefix = keyPrefix;
+			return this;
+		}
+
+		public boolean isUseKeyPrefix() {
+			return this.useKeyPrefix;
+		}
+
+		public Redis setUseKeyPrefix(boolean useKeyPrefix) {
+			this.useKeyPrefix = useKeyPrefix;
+			return this;
+		}
+	}
+
 }

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

@@ -20,6 +20,7 @@ import java.util.LinkedHashSet;
 import java.util.List;
 
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
+import org.springframework.boot.autoconfigure.cache.CacheProperties.Redis;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.data.redis.RedisAutoConfiguration;
@@ -36,6 +37,7 @@ import org.springframework.data.redis.connection.RedisConnectionFactory;
  *
  * @author Stephane Nicoll
  * @author Mark Paluch
+ * @author Ryon Day
  * @since 1.3.0
  */
 @Configuration
@@ -58,7 +60,7 @@ class RedisCacheConfiguration {
 	@Bean
 	public RedisCacheManager cacheManager(RedisConnectionFactory redisConnectionFactory) {
 		RedisCacheManagerBuilder builder = RedisCacheManager
-				.builder(redisConnectionFactory);
+				.builder(redisConnectionFactory).cacheDefaults(getConfiguration());
 		List<String> cacheNames = this.cacheProperties.getCacheNames();
 		if (!cacheNames.isEmpty()) {
 			builder.initialCacheNames(new LinkedHashSet<>(cacheNames));
@@ -66,4 +68,26 @@ class RedisCacheConfiguration {
 		return this.customizerInvoker.customize(builder.build());
 	}
 
+	private org.springframework.data.redis.cache.RedisCacheConfiguration getConfiguration() {
+
+		Redis redisProperties = this.cacheProperties.getRedis();
+
+		org.springframework.data.redis.cache.RedisCacheConfiguration config = org.springframework.data.redis.cache.RedisCacheConfiguration
+				.defaultCacheConfig().entryTtl(redisProperties.getTtl());
+
+		if (redisProperties.getKeyPrefix() != null) {
+			config = config.prefixKeysWith(redisProperties.getKeyPrefix());
+		}
+
+		if (!redisProperties.isCacheNullValues()) {
+			config = config.disableCachingNullValues();
+		}
+
+		if (!redisProperties.isUseKeyPrefix()) {
+			config = config.disableKeyPrefix();
+		}
+
+		return config;
+	}
+
 }

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

@@ -90,6 +90,7 @@ import static org.mockito.Mockito.verify;
  * @author Stephane Nicoll
  * @author Eddú Meléndez
  * @author Mark Paluch
+ * @author Ryon Day
  */
 @RunWith(ModifiedClassPathRunner.class)
 @ClassPathExclusions("hazelcast-client-*.jar")
@@ -280,14 +281,25 @@ public class CacheAutoConfigurationTests {
 	@Test
 	public void redisCacheExplicit() {
 		this.contextRunner.withUserConfiguration(RedisCacheConfiguration.class)
-				.withPropertyValues("spring.cache.type=redis").run((context) -> {
+				.withPropertyValues("spring.cache.type=redis",
+						"spring.cache.redis.ttl=PT15M",
+						"spring.cache.redis.keyPrefix=foo",
+						"spring.cache.redis.useKeyPrefix=false",
+						"spring.cache.redis.cacheNullValues=false")
+				.run((context) -> {
 					RedisCacheManager cacheManager = getCacheManager(context,
 							RedisCacheManager.class);
 					assertThat(cacheManager.getCacheNames()).isEmpty();
-					assertThat(
-							((org.springframework.data.redis.cache.RedisCacheConfiguration) new DirectFieldAccessor(
-									cacheManager).getPropertyValue("defaultCacheConfig"))
-											.usePrefix()).isTrue();
+
+					org.springframework.data.redis.cache.RedisCacheConfiguration redisCacheConfiguration = (org.springframework.data.redis.cache.RedisCacheConfiguration) new DirectFieldAccessor(
+							cacheManager).getPropertyValue("defaultCacheConfig");
+
+					assertThat(redisCacheConfiguration.usePrefix()).isFalse();
+					assertThat(redisCacheConfiguration.getKeyPrefix()).contains("foo");
+					assertThat(redisCacheConfiguration.getTtl())
+							.isEqualTo(java.time.Duration.ofMinutes(15));
+					assertThat(redisCacheConfiguration.getAllowCacheNullValues())
+							.isFalse();
 				});
 	}
 
@@ -309,6 +321,15 @@ public class CacheAutoConfigurationTests {
 					RedisCacheManager cacheManager = getCacheManager(context,
 							RedisCacheManager.class);
 					assertThat(cacheManager.getCacheNames()).containsOnly("foo", "bar");
+
+					org.springframework.data.redis.cache.RedisCacheConfiguration redisCacheConfiguration = (org.springframework.data.redis.cache.RedisCacheConfiguration) new DirectFieldAccessor(
+							cacheManager).getPropertyValue("defaultCacheConfig");
+					assertThat(redisCacheConfiguration.usePrefix()).isTrue();
+					assertThat(redisCacheConfiguration.getKeyPrefix()).isEmpty();
+					assertThat(redisCacheConfiguration.getTtl())
+							.isEqualTo(java.time.Duration.ofMinutes(0));
+					assertThat(redisCacheConfiguration.getAllowCacheNullValues())
+							.isTrue();
 				});
 	}