[[beans-resource-annotation]]
= Injection with `@Resource`

Spring also supports injection by using the JSR-250 `@Resource` annotation
(`jakarta.annotation.Resource`) on fields or bean property setter methods.
This is a common pattern in Jakarta EE: for example, in JSF-managed beans and JAX-WS
endpoints. Spring supports this pattern for Spring-managed objects as well.

`@Resource` takes a name attribute. By default, Spring interprets that value as
the bean name to be injected. In other words, it follows by-name semantics,
as demonstrated in the following example:

--
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
	public class SimpleMovieLister {

		private MovieFinder movieFinder;

		@Resource(name="myMovieFinder") // <1>
		public void setMovieFinder(MovieFinder movieFinder) {
			this.movieFinder = movieFinder;
		}
	}
----
<1> This line injects a `@Resource`.

Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
class SimpleMovieLister {

	@Resource(name="myMovieFinder") // <1>
	private lateinit var movieFinder:MovieFinder
}
----
<1> This line injects a `@Resource`.
======
--


If no name is explicitly specified, the default name is derived from the field name or
setter method. In case of a field, it takes the field name. In case of a setter method,
it takes the bean property name. The following example is going to have the bean
named `movieFinder` injected into its setter method:

--
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======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
	public class SimpleMovieLister {

		private MovieFinder movieFinder;

		@Resource
		public void setMovieFinder(MovieFinder movieFinder) {
			this.movieFinder = movieFinder;
		}
	}
----

Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
	class SimpleMovieLister {

		@set:Resource
		private lateinit var movieFinder: MovieFinder

	}
----
======
--

NOTE: The name provided with the annotation is resolved as a bean name by the
`ApplicationContext` of which the `CommonAnnotationBeanPostProcessor` is aware.
The names can be resolved through JNDI if you configure Spring's
{spring-framework-api}/jndi/support/SimpleJndiBeanFactory.html[`SimpleJndiBeanFactory`]
explicitly. However, we recommend that you rely on the default behavior and
use Spring's JNDI lookup capabilities to preserve the level of indirection.

In the exclusive case of `@Resource` usage with no explicit name specified, and similar
to `@Autowired`, `@Resource` finds a primary type match instead of a specific named bean
and resolves well known resolvable dependencies: the `BeanFactory`,
`ApplicationContext`, `ResourceLoader`, `ApplicationEventPublisher`, and `MessageSource`
interfaces.

Thus, in the following example, the `customerPreferenceDao` field first looks for a bean
named "customerPreferenceDao" and then falls back to a primary type match for the type
`CustomerPreferenceDao`:

--
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes",role="primary"]
----
	public class MovieRecommender {

		@Resource
		private CustomerPreferenceDao customerPreferenceDao;

		@Resource
		private ApplicationContext context; // <1>

		public MovieRecommender() {
		}

		// ...
	}
----
<1> The `context` field is injected based on the known resolvable dependency type:
`ApplicationContext`.

Kotlin::
+
[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
----
	class MovieRecommender {

		@Resource
		private lateinit var customerPreferenceDao: CustomerPreferenceDao


		@Resource
		private lateinit var context: ApplicationContext // <1>

		// ...
	}
----
<1> The `context` field is injected based on the known resolvable dependency type:
`ApplicationContext`.
======
--

