org.omnifaces.util.Beans Maven / Gradle / Ivy
/*
* Copyright 2013 OmniFaces.
*
* 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 org.omnifaces.util;
import java.lang.annotation.Annotation;
import java.util.Map;
import javax.enterprise.context.spi.AlterableContext;
import javax.enterprise.context.spi.Context;
import javax.enterprise.context.spi.CreationalContext;
import javax.enterprise.inject.Produces;
import javax.enterprise.inject.Stereotype;
import javax.enterprise.inject.Typed;
import javax.enterprise.inject.spi.Annotated;
import javax.enterprise.inject.spi.Bean;
import javax.enterprise.inject.spi.BeanManager;
import javax.enterprise.inject.spi.InjectionPoint;
/**
*
* Collection of utility methods for the CDI API that are mainly shortcuts for obtaining stuff from the
* {@link BeanManager}.
*
*
Usage
*
* Some examples:
*
* // Get the CDI managed bean reference (proxy) of the given bean class.
* SomeBean someBean = Beans.getReference(SomeBean.class);
*
* // Get the CDI managed bean instance (actual) of the given bean class.
* SomeBean someBean = Beans.getInstance(SomeBean.class);
*
* // Get all currently active CDI managed bean instances in the session scope.
* Map<Object, String> activeSessionScopedBeans = Beans.getActiveInstances(SessionScope.class);
*
* // Destroy any currently active CDI managed bean instance of given bean class.
* Beans.destroy(SomeBean.class);
*
*
* The "native" CDI way would otherwise look like this:
*
* // Get the CDI managed bean reference (proxy) of the given bean class.
* Set<Bean<?>> beans = beanManager.getBeans(SomeBean.class);
* Bean<SomeBean> bean = (Bean<SomeBean>) beanManager.resolve(beans);
* CreationalContext<SomeBean> context = beanManager.createCreationalContext(bean);
* SomeBean someBean = (SomeBean) beanManager.getReference(bean, SomeBean.class, context);
*
*
* If you need a dependency-free way of obtaining the CDI managed bean reference (e.g. when you want to write code which
* should also run on Tomcat), use {@link org.omnifaces.config.BeanManager} enum instead.
*
* @author Bauke Scholtz
* @since 1.6.1
* @see BeansLocal
*/
@Typed
public final class Beans {
// Constructors ---------------------------------------------------------------------------------------------------
private Beans() {
// Hide constructor.
}
// Utility --------------------------------------------------------------------------------------------------------
/**
* Returns the CDI bean manager.
* @return The CDI bean manager.
* @since 2.0
* @see org.omnifaces.config.BeanManager#get()
*/
public static BeanManager getManager() {
return org.omnifaces.config.BeanManager.INSTANCE.get();
}
/**
* Returns the CDI managed bean representation of the given bean class.
* @param The generic CDI managed bean type.
* @param beanClass The CDI managed bean class.
* @return The CDI managed bean representation of the given bean class, or null if there is none.
* @see BeanManager#getBeans(String)
* @see BeanManager#resolve(java.util.Set)
*/
public static Bean resolve(Class beanClass) {
return BeansLocal.resolve(getManager(), beanClass);
}
/**
* Returns the CDI managed bean reference (proxy) of the given bean class.
* Note that this actually returns a client proxy and the underlying actual instance is thus always auto-created.
* @param The expected return type.
* @param beanClass The CDI managed bean class.
* @return The CDI managed bean reference (proxy) of the given class, or null if there is none.
* @see #resolve(Class)
* @see #getReference(Bean)
*/
public static T getReference(Class beanClass) {
return BeansLocal.getReference(getManager(), beanClass);
}
/**
* Returns the CDI managed bean reference (proxy) of the given bean representation.
* Note that this actually returns a client proxy and the underlying actual instance is thus always auto-created.
* @param The expected return type.
* @param bean The CDI managed bean representation.
* @return The CDI managed bean reference (proxy) of the given bean, or null if there is none.
* @see BeanManager#createCreationalContext(javax.enterprise.context.spi.Contextual)
* @see BeanManager#getReference(Bean, java.lang.reflect.Type, javax.enterprise.context.spi.CreationalContext)
*/
public static T getReference(Bean bean) {
return BeansLocal.getReference(getManager(), bean);
}
/**
* Returns the CDI managed bean instance (actual) of the given bean class and creates one if one doesn't exist.
* @param The expected return type.
* @param beanClass The CDI managed bean class.
* @return The CDI managed bean instance (actual) of the given bean class, or null if there is none.
* @since 1.8
* @see #getInstance(Class, boolean)
*/
public static T getInstance(Class beanClass) {
return BeansLocal.getInstance(getManager(), beanClass);
}
/**
* Returns the CDI managed bean instance (actual) of the given bean class and creates one if one doesn't exist and
* create argument is true, otherwise don't create one and return null if
* there's no current instance.
* @param The expected return type.
* @param beanClass The CDI managed bean class.
* @param create Whether to create create CDI managed bean instance if one doesn't exist.
* @return The CDI managed bean instance (actual) of the given bean class, or null if there is none
* and/or the create argument is false.
* @since 1.7
* @see #resolve(Class)
* @see #getInstance(Bean, boolean)
*/
public static T getInstance(Class beanClass, boolean create) {
return BeansLocal.getInstance(getManager(), beanClass, create);
}
/**
* Returns the CDI managed bean instance (actual) of the given bean representation and creates one if one doesn't
* exist and create argument is true, otherwise don't create one and return
* null if there's no current instance.
* @param The expected return type.
* @param bean The CDI managed bean representation.
* @param create Whether to create create CDI managed bean instance if one doesn't exist.
* @return The CDI managed bean instance (actual) of the given bean, or null if there is none and/or
* the create argument is false.
* @since 1.7
* @see BeanManager#getContext(Class)
* @see BeanManager#createCreationalContext(javax.enterprise.context.spi.Contextual)
* @see Context#get(javax.enterprise.context.spi.Contextual, javax.enterprise.context.spi.CreationalContext)
*/
public static T getInstance(Bean bean, boolean create) {
return BeansLocal.getInstance(getManager(), bean, create);
}
/**
* Returns all active CDI managed bean instances in the given CDI managed bean scope. The map key represents
* the active CDI managed bean instance and the map value represents the CDI managed bean name, if any.
* @param The generic CDI managed bean scope type.
* @param scope The CDI managed bean scope, e.g. RequestScoped.class.
* @return All active CDI managed bean instances in the given CDI managed bean scope.
* @since 1.7
* @see BeanManager#getBeans(String)
* @see BeanManager#getContext(Class)
* @see Context#get(javax.enterprise.context.spi.Contextual)
*/
public static Map getActiveInstances(Class scope) {
return BeansLocal.getActiveInstances(getManager(), scope);
}
/**
* Destroy the currently active instance of the given CDI managed bean class.
* @param The generic CDI managed bean type.
* @param beanClass The CDI managed bean class.
* @since 2.0
* @see #resolve(Class)
* @see #destroy(Bean)
*/
public static void destroy(Class beanClass) {
BeansLocal.destroy(getManager(), beanClass);
}
/**
* Destroy the currently active instance of the given CDI managed bean representation.
* @param The generic CDI managed bean type.
* @param bean The CDI managed bean representation.
* @throws IllegalArgumentException When the given CDI managed bean type is actually not put in an alterable
* context.
* @since 2.0
* @see BeanManager#getContext(Class)
* @see AlterableContext#destroy(javax.enterprise.context.spi.Contextual)
*/
public static void destroy(Bean bean) {
BeansLocal.destroy(getManager(), bean);
}
/**
* Get program element annotation of a certain annotation type. The difference with
* {@link Annotated#getAnnotation(Class)} is that this method will recursively search inside all {@link Stereotype}
* annotations.
* @param The generic annotation type.
* @param annotated A Java program element that can be annotated.
* @param annotationType The class of the annotation type.
* @return The program element annotation of the given annotation type if it could be found, otherwise
* null.
* @since 1.8
*/
public static A getAnnotation(Annotated annotated, Class annotationType) {
return BeansLocal.getAnnotation(getManager(), annotated, annotationType);
}
/**
* Gets the current injection point when called from a context where injection is taking place (e.g. from a producer).
*
* This is mostly intended to be used from within a dynamic producer {@link Bean}. For a "regular" producer (using {@link Produces})
* an InjectionPoint can either be injected into the bean that contains the producer method, or directly provided as argument
* of said method.
*
* @param creationalContext a {@link CreationalContext} used to manage objects with a
* {@link javax.enterprise.context.Dependent} scope
* @return the current injection point when called from a context where injection is taking place (e.g. from a producer)
*/
public static InjectionPoint getCurrentInjectionPoint(CreationalContext creationalContext) {
return BeansLocal.getCurrentInjectionPoint(getManager(), creationalContext);
}
/**
* Returns the qualifier annotation of the given qualifier class from the given injection point.
* @param The generic annotation type.
* @param injectionPoint The injection point to obtain the qualifier annotation of the given qualifier class from.
* @param qualifierClass The class of the qualifier annotation to be looked up in the given injection point.
* @return The qualifier annotation of the given qualifier class from the given injection point.
* @since 2.1
*/
public static A getQualifier(InjectionPoint injectionPoint, Class qualifierClass) {
for (Annotation annotation : injectionPoint.getQualifiers()) {
if (qualifierClass.isAssignableFrom(annotation.getClass())) {
return qualifierClass.cast(annotation);
}
}
return null;
}
}