Package org.apache.logging.log4j.plugins

Annotation Interface Factory

@Target(METHOD)
@Retention(RUNTIME)
@Documented
@FactoryType
public @interface Factory

Marks a method as a factory for supplying sources of instances of the method's return type. Factory methods are comparable to bean factories from other dependency injection frameworks such as @Bean in the Spring Framework or @Provides in the Guice framework. There are a few rules related to factory methods:

• Factory methods must be non-abstract methods of a bean class (static or not).
• If the bean class's scope is different from the provider bean, then it must be a larger scope.
• If factory methods return a nullable value, then it must be unscoped.
• Factory method return type must not be a type variable.
• Factory method return type may be parameterized only if it specifies actual types or a type variable for each parameter, the latter case also required to be unscoped.
• Classes may declare multiple factory methods to create different instance types or qualified instances.
• Factory methods are not inherited by subclasses.
• Classes annotated with Configurable can specify a static factory method instead of relying on Inject.