[id='cdi_inject_embed']
= Injecting Embedded Caches
Set up CDI beans to inject embedded caches.

.Procedure

. Create a cache qualifier annotation.
+
[source,java]
----
...
import javax.inject.Qualifier;

@Qualifier
@Target({ElementType.FIELD, ElementType.PARAMETER, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface GreetingCache { <1>
}
----
+
<1> creates a `@GreetingCache` qualifier.
+
. Add a producer method that defines the cache configuration.
+
[source,java]
----
...
import org.infinispan.configuration.cache.Configuration;
import org.infinispan.configuration.cache.ConfigurationBuilder;
import org.infinispan.cdi.ConfigureCache;
import javax.enterprise.inject.Produces;

public class Config {

    @ConfigureCache("mygreetingcache") <1>
    @GreetingCache <2>
    @Produces
    public Configuration greetingCacheConfiguration() {
        return new ConfigurationBuilder()
                    .memory()
                        .size(1000)
                    .build();
    }
}
----
+
<1> names the cache to inject.
<2> adds the cache qualifier.
+
. Add a producer method that creates a clustered cache manager, if required
+
[source,java]
----
...
package org.infinispan.configuration.global.GlobalConfigurationBuilder;

public class Config {

    @GreetingCache <1>
    @Produces
    @ApplicationScoped <2>
    public EmbeddedCacheManager defaultClusteredCacheManager() { <3>
      return new DefaultCacheManager(
        new GlobalConfigurationBuilder().transport().defaultTransport().build();
   }
}
----
+
<1> adds the cache qualifier.
<2> creates the bean once for the application. Producers that create cache managers should always include the `@ApplicationScoped` annotation to avoid creating multiple cache managers.
<3> creates a new `DefaultCacheManager` instance that is bound to the `@GreetingCache` qualifier.
+
[NOTE]
====
Cache managers are heavy weight objects. Having more than one cache manager
running in your application can degrade performance. When injecting multiple
caches, either add the qualifier of each cache to the cache manager producer
method or do not add any qualifier.
====
. Add the `@GreetingCache` qualifier to your cache injection point.
+
----
...
import javax.inject.Inject;

public class GreetingService {

    @Inject @GreetingCache
    private Cache<String, String> cache;

    public String greet(String user) {
        String cachedValue = cache.get(user);
        if (cachedValue == null) {
            cachedValue = "Hello " + user;
            cache.put(user, cachedValue);
        }
        return cachedValue;
    }
}
----
