io.micronaut.inject.BeanDefinitionReference Maven / Gradle / Ivy
/*
* Copyright 2017-2020 original authors
*
* 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
*
* https://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 io.micronaut.inject;
import io.micronaut.context.BeanContext;
import io.micronaut.context.annotation.ConfigurationReader;
import io.micronaut.context.annotation.DefaultScope;
import io.micronaut.core.annotation.AnnotationMetadata;
import io.micronaut.core.annotation.Internal;
import javax.inject.Singleton;
/**
* A bean definition reference provides a reference to a {@link BeanDefinition} thus
* allowing for soft loading of bean definitions without loading the actual types.
*
* This interface implements {@link io.micronaut.core.annotation.AnnotationMetadataProvider} thus allowing the bean
* metadata to be introspected safely without loading the class or the annotations themselves.
*
* The actual bean will be loaded upon calling the {@link #load()} method. Note that consumers of this interface
* should call {@link #isPresent()} prior to loading to ensure an error does not occur
*
* The class can also decide whether to abort loading the definition by returning null
*
* This interface extends the {@link BeanType} interface which is shared between {@link BeanDefinition} and this type. In addition a
* reference can be enabled or disabled (see {@link BeanContextConditional#isEnabled(BeanContext)})
*
* @see BeanType
* @see BeanDefinition
* @see BeanContextConditional
* @param The bean type
* @author Graeme Rocher
* @since 1.0
*/
@Internal
public interface BeanDefinitionReference extends BeanType {
/**
* @return The class name of the backing {@link BeanDefinition}
*/
String getBeanDefinitionName();
/**
* Loads the bean definition.
*
* @return The loaded component definition or null if it shouldn't be loaded
*/
BeanDefinition load();
/**
* Loads the bean definition for the current {@link BeanContext}.
*
* @param context The bean context
* @return The loaded bean definition or null if it shouldn't be loaded
*/
BeanDefinition load(BeanContext context);
/**
* @return Is this class context scope
*/
boolean isContextScope();
/**
* @return Is the underlying bean type present on the classpath
*/
boolean isPresent();
/**
* @return Is this bean a singleton.
* @since 2.0
*/
default boolean isSingleton() {
AnnotationMetadata am = getAnnotationMetadata();
return am.hasDeclaredStereotype(Singleton.class) ||
am.classValue(DefaultScope.class).map(t -> t == Singleton.class).orElse(false);
}
/**
* @return Is this bean a configuration properties.
* @since 2.0
*/
default boolean isConfigurationProperties() {
return getAnnotationMetadata().hasDeclaredStereotype(ConfigurationReader.class);
}
}