jakarta.enterprise.context.Dependent Maven / Gradle / Ivy
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* Copyright 2010, Red Hat, Inc., and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package jakarta.enterprise.context;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import java.lang.annotation.Documented;
import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import jakarta.enterprise.context.spi.Contextual;
import jakarta.enterprise.context.spi.CreationalContext;
import jakarta.enterprise.util.AnnotationLiteral;
import jakarta.inject.Scope;
import jakarta.enterprise.context.spi.Context;
import jakarta.enterprise.inject.Instance;
/**
*
* Specifies that a bean belongs to the dependent pseudo-scope.
*
*
*
* Beans declared with scope @Dependent behave differently to beans with other built-in scope types. When a bean is
* declared to have scope @Dependent:
*
*
*
* - No injected instance of the bean is ever shared between multiple injection points.
* - Any instance of the bean injected into an object that is being created by the container is bound to the lifecycle of the
* newly created object.
* - When a Unified EL expression in a JSF or JSP page that refers to the bean by its EL name is evaluated, at most one
* instance of the bean is instantiated. This instance exists to service just a single evaluation of the EL expression. It is
* reused if the bean EL name appears multiple times in the EL expression, but is never reused when the EL expression is
* evaluated again, or when another EL expression is evaluated.
* - Any instance of the bean that receives a producer method, producer field, disposer method or observer method invocation
* exists to service that invocation only.
* - Any instance of the bean injected into method parameters of a disposer method or observer method exists to service the
* method invocation only.
*
*
*
* Every invocation of the {@link Context#get(Contextual, CreationalContext)} operation of the
* context object for the @Dependent scope returns a new instance of the given bean.
*
*
*
* Every invocation of the {@link Context#get(Contextual)} operation of the context object for the
* @Dependent scope returns a null value.
*
*
*
* The @Dependent scope is always active.
*
*
*
* Many instances of beans with scope @Dependent belong to some other bean or Java EE component class instance and are
* called dependent objects.
*
*
*
* - Instances of decorators and interceptors are dependent objects of the bean instance they decorate.
* - An instance of a bean with scope
@Dependent injected into a field, bean constructor or initializer method is a
* dependent object of the bean or Java EE component class instance into which it was injected.
* - An instance of a bean with scope
@Dependent injected into a producer method is a dependent object of the
* producer method bean instance that is being produced.
* - An instance of a bean with scope
@Dependent obtained by direct invocation of an
* {@link Instance} is a dependent object of the instance of {@link Instance}.
*
*
*
* When the container destroys an instance of a bean or of any Java EE component class supporting injection, the container
* destroys all its dependent objects, after the @PreDestroy callback completes and after the servlet
* destroy() method is called.
*
*
* @author Gavin King
* @author Pete Muir
*/
@Target({ METHOD, TYPE, FIELD })
@Retention(RUNTIME)
@Documented
@Scope
@Inherited
public @interface Dependent {
/**
* Supports inline instantiation of the {@link Dependent} annotation.
*
* @author Martin Kouba
* @since 2.0
*/
public final static class Literal extends AnnotationLiteral implements Dependent {
public static final Literal INSTANCE = new Literal();
private static final long serialVersionUID = 1L;
}
}