Merge pull request #19819 from nosan

* pr/19819:
  Polish "Document RedisCacheManagerBuilderCustomizer"
  Document RedisCacheManagerBuilderCustomizer

Closes gh-19819

spring-boot-project/spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc

@@ -4774,8 +4774,17 @@ For instance, the following configuration creates `cache1` and `cache2` caches w
 NOTE: By default, a key prefix is added so that, if two separate caches use the same key, Redis does not have overlapping keys and cannot return invalid values.
 We strongly recommend keeping this setting enabled if you create your own `RedisCacheManager`.
 
-TIP: You can take full control of the configuration by adding a `RedisCacheConfiguration` `@Bean` of your own.
-This can be useful if you're looking for customizing the serialization strategy.
+TIP: You can take full control of the default configuration by adding a `RedisCacheConfiguration` `@Bean` of your own.
+This can be useful if you're looking for customizing the default serialization strategy.
+
+If you need more control over the configuration, consider registering a `RedisCacheManagerBuilderCustomizer` bean.
+The following example shows a customizer that configures a specific time to live for `cache1` and `cache2`:
+
+[source,java,indent=0]
+----
+include::{code-examples}/cache/RedisCacheManagerCustomizationExample.java[tag=configuration]
+----
+
 
 
 

spring-boot-project/spring-boot-docs/src/main/java/org/springframework/boot/docs/cache/RedisCacheManagerCustomizationExample.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2012-2020 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
+ *
+ *      https://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.boot.docs.cache;
+
+import java.time.Duration;
+
+import org.springframework.boot.autoconfigure.cache.RedisCacheManagerBuilderCustomizer;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.redis.cache.RedisCacheConfiguration;
+
+/**
+ * An example how to customize {@code RedisCacheManagerBuilder} via
+ * {@code RedisCacheManagerBuilderCustomizer}.
+ *
+ * @author Dmytro Nosan
+ */
+@Configuration(proxyBeanMethods = false)
+public class RedisCacheManagerCustomizationExample {
+
+	// tag::configuration[]
+	@Bean
+	public RedisCacheManagerBuilderCustomizer myRedisCacheManagerBuilderCustomizer() {
+		return (builder) -> builder
+				.withCacheConfiguration("cache1",
+						RedisCacheConfiguration.defaultCacheConfig().entryTtl(Duration.ofSeconds(10)))
+				.withCacheConfiguration("cache2",
+						RedisCacheConfiguration.defaultCacheConfig().entryTtl(Duration.ofMinutes(1)));
+
+	}
+	// end::configuration[]
+
+}