spring-boot/spring-boot-samples/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`
* `Redis`
* `Guava`
* Simple provider based on `ConcurrentHashMap`

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 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.

=== 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`.

=== 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

Simply add the `org.infinispan:infinispan-spring4` 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.

=== JCache (JSR-107)

You do not need to use a JSR-107 compliant `CacheManager` to use the standard
annotations. As a matter of a fact, this sample uses by default the standard annotations
with a simple map-based `CacheManager` by default. If you want to configure your cache
infrastructure via the standard, you need a compliant implementation. You could try
the following:

* `Hazelcast`: add `com.hazelcast:hazelcast`
* `Infinispan`: add `org.infinispan:infinispan-jcache`


Since Spring Boot supports the native cache library and the JCache wrapper, you
should set the `spring.cache.type` property to `jcache` to specify that you want the
cache manager to be auto-configured that way.

=== Redis

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

=== 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.