spring-boot-sample-cache

Spring Boot Cache Sample

This sample demonstrates the caching auto-configuration support. Spring’s caching abstraction is supported by many caching libraries, including:

• Any compliant JSR-107 (JCache) provider

• EhCache

• Hazelcast

• Infinispan

• Couchbase

• Redis

• Caffeine

• Guava

• Simple provider based on ConcurrentHashMap

• Generic provider based on org.springframework.Cache bean definition(s)

The sample defines a simple CountryService that caches countries by ISO code. When the application starts a client invokes the service with a random code every 500ms. You can look at the /metrics endpoint to review the cache statistics if your chosen caching provider is supported.

Using the JSR-107 annotations

The sample uses Spring’s cache annotation. If you want to use the JSR-107 annotations instead, simply add the javax.cache:cache-api dependency to the project. No further configuration is necessary.

Note	You can use the JSR-107 annotations with any cache provider; a JSR-107 compliant cache provider is not necessary.

Using a different cache provider

Initially, the project does not define any caching library so the abstraction works on simple ConcurrentHashMap-based caches. You can try out your favorite caching library as explained below.

JCache (JSR-107)

If you want to configure your cache infrastructure via the standard, you need a compliant implementation and the JSR-107 api. You first need to add javax.cache:cache-api to your project. Then you could try the following:

• EhCache 3: add org.ehcache:ehcache

• Hazelcast: add com.hazelcast:hazelcast

• Infinispan: add org.infinispan:infinispan-jcache

Tip	Certain cache providers do not create a default cache on-the-fly if it does not exist so you might need to update the sample to create the caches on startup or specify the location to the provider-specific file via the spring.cache.jcache.config property.

Note	Any other JSR-107 compliant provider is also supported but Spring Boot may not offer a dependency management entry for it. You will have to add it with the version of the library that you want to use.

EhCache 2.x

Simply add the net.sf.ehcache:ehcache dependency to the project. Since there is a default ehcache.xml configuration file at the root of the classpath, it is automatically used to configure the underlying CacheManager. Note that EhCache 3 uses a different format and doesn’t default to ehcache.xml anymore. Check the documentation for more details.

Hazelcast

Both com.hazelcast:hazelcast and com.hazelcast:hazelcast-spring should be added to the project to enable support for Hazelcast. Since there is a default hazelcast.xml configuration file at the root of the classpath, it is used to automatically configure the underlying HazelcastInstance.

Infinispan

Add the org.infinispan:infinispan-spring4-embedded dependency to enable support for Infinispan. There is no default location that Infinispan uses to look for a config file so if you don’t specify anything it will bootstrap on a hardcoded default. You can set the spring.cache.infinispan.config property to use the provided infinispan.xml configuration instead.

Couchbase

Add the java-client and couchbase-spring-cache dependencies and make sure that you have setup at least a spring.couchbase.bootstrap-hosts property.

Redis

Add the spring-boot-starter-data-redis and make sure it is configured properly (by default, a redis instance with the default settings is expected on your local box).

Caffeine

Simply add the com.github.ben-manes.caffeine:caffeine dependency to enable support for Caffeine. You can customize how caches are created in different ways, see application.properties for an example and the documentation for more details.

Guava

Spring Boot does not provide any dependency management for Guava so you’ll have to add the com.google.guava:guava dependency with a version. You can customize how caches are created in different ways, see application.properties for an example and the documentation for more details.