infra.beans.factory.config.BeanDefinition Maven / Gradle / Ivy
/*
* Copyright 2017 - 2024 the original author or authors.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see [https://www.gnu.org/licenses/]
*/
package infra.beans.factory.config;
import java.lang.reflect.Method;
import infra.beans.BeanMetadataElement;
import infra.beans.PropertyValues;
import infra.core.AttributeAccessor;
import infra.core.ResolvableType;
import infra.lang.Constant;
import infra.lang.Nullable;
/**
* A BeanDefinition describes a bean instance, which has property values,
* constructor argument values, and further information supplied by
* concrete implementations.
*
* This is just a minimal interface: The main intention is to allow a
* {@link BeanFactoryPostProcessor} to introspect and modify property values
* and other bean metadata.
*
* @author Harry Yang
* @since 2019-02-01 12:23
*/
public interface BeanDefinition extends AttributeAccessor, BeanMetadataElement {
// @since 4.0
Method[] EMPTY_METHOD = Constant.EMPTY_METHODS;
/**
* Scope identifier for the standard singleton scope: {@value}.
*
Note that extended bean factories might support further scopes.
*
* @see #setScope
* @see Scope#SINGLETON
*/
String SCOPE_SINGLETON = Scope.SINGLETON;
/**
* Scope identifier for the standard prototype scope: {@value}.
*
Note that extended bean factories might support further scopes.
*
* @see #setScope
* @see Scope#PROTOTYPE
*/
String SCOPE_PROTOTYPE = Scope.PROTOTYPE;
/**
* Role hint indicating that a {@code BeanDefinition} is a major part
* of the application. Typically， corresponds to a user-defined bean.
*/
int ROLE_APPLICATION = 0;
/**
* Role hint indicating that a {@code BeanDefinition} is a supporting
* part of some larger configuration.
*/
int ROLE_SUPPORT = 1;
/**
* Role hint indicating that a {@code BeanDefinition} is providing an
* entirely background role and has no relevance to the end-user. This hint is
* used when registering beans that are completely part of the internal workings
*/
int ROLE_INFRASTRUCTURE = 2;
// Modifiable attributes
/**
* Set the name of the parent definition of this bean definition, if any.
*/
void setParentName(@Nullable String parentName);
/**
* Return the name of the parent definition of this bean definition, if any.
*/
@Nullable
String getParentName();
/**
* Specify the bean class name of this bean definition.
*
The class name can be modified during bean factory post-processing,
* typically replacing the original class name with a parsed variant of it.
*
* @see #setParentName
* @see #setFactoryBeanName
* @see #setFactoryMethodName
*/
void setBeanClassName(@Nullable String beanClassName);
/**
* Return the current bean class name of this bean definition.
*
Note that this does not have to be the actual class name used at runtime, in
* case of a child definition overriding/inheriting the class name from its parent.
* Also, this may just be the class that a factory method is called on, or it may
* even be empty in case of a factory bean reference that a method is called on.
* Hence, do not consider this to be the definitive bean type at runtime but
* rather only use it for parsing purposes at the individual bean definition level.
*
* @see #getParentName()
* @see #getFactoryBeanName()
* @see #getFactoryMethodName()
*/
@Nullable
String getBeanClassName();
/**
* Override the target scope of this bean, specifying a new scope name.
*
* @see #SCOPE_SINGLETON
* @see #SCOPE_PROTOTYPE
*/
void setScope(@Nullable String scope);
/**
* Return the name of the current target scope for this bean,
* or {@code null} if not known yet.
*/
@Nullable
String getScope();
/**
* Set whether this bean should be lazily initialized.
*
If {@code false}, the bean will get instantiated on startup by bean
* factories that perform eager initialization of singletons.
*/
void setLazyInit(boolean lazyInit);
/**
* Return whether this bean should be lazily initialized, i.e. not
* eagerly instantiated on startup. Only applicable to a singleton bean.
*/
boolean isLazyInit();
/**
* Set the names of the beans that this bean depends on being initialized.
* The bean factory will guarantee that these beans get initialized first.
*
Note that dependencies are normally expressed through bean properties or
* constructor arguments. This property should just be necessary for other kinds
* of dependencies like statics (*ugh*) or database preparation on startup.
*/
void setDependsOn(@Nullable String... dependsOn);
/**
* Return the bean names that this bean depends on.
*/
@Nullable
String[] getDependsOn();
/**
* Set whether this bean is a candidate for getting autowired into some other bean.
*
Note that this flag is designed to only affect type-based autowiring.
* It does not affect explicit references by name, which will get resolved even
* if the specified bean is not marked as an autowire candidate. As a consequence,
* autowiring by name will nevertheless inject a bean if the name matches.
*/
void setAutowireCandidate(boolean autowireCandidate);
/**
* Return whether this bean is a candidate for getting autowired into some other bean.
*/
boolean isAutowireCandidate();
/**
* Set whether this bean is a primary autowire candidate.
*
If this value is {@code true} for exactly one bean among multiple
* matching candidates, it will serve as a tie-breaker.
*/
void setPrimary(boolean primary);
/**
* Return whether this bean is a primary autowire candidate.
*/
boolean isPrimary();
/**
* Set whether this bean is a fallback autowire candidate.
*
If this value is {@code true} for all beans but one among multiple
* matching candidates, the remaining bean will be selected.
*
* @see #setPrimary
*/
void setFallback(boolean fallback);
/**
* Return whether this bean is a fallback autowire candidate.
*/
boolean isFallback();
/**
* Specify the factory bean to use, if any.
* This is the name of the bean to call the specified factory method on.
*
A factory bean name is only necessary for instance-based factory methods.
* For static factory methods, the method will be derived from the bean class.
*
* @see #setFactoryMethodName
* @see #setBeanClassName
*/
void setFactoryBeanName(@Nullable String factoryBeanName);
/**
* Return the factory bean name, if any.
*
This will be {@code null} for static factory methods which will
* be derived from the bean class instead.
*
* @see #getFactoryMethodName()
* @see #getBeanClassName()
*/
@Nullable
String getFactoryBeanName();
/**
* Specify a factory method, if any. This method will be invoked with
* constructor arguments, or with no arguments if none are specified.
* The method will be invoked on the specified factory bean, if any,
* or otherwise as a static method on the local bean class.
*
* @see #setFactoryBeanName
* @see #setBeanClassName
*/
void setFactoryMethodName(@Nullable String factoryMethodName);
/**
* Return a factory method, if any.
*/
@Nullable
String getFactoryMethodName();
/**
* Return the constructor argument values for this bean.
*
The returned instance can be modified during bean factory post-processing.
*
* @return the ConstructorArgumentValues object (never {@code null})
*/
ConstructorArgumentValues getConstructorArgumentValues();
/**
* Return if there are constructor argument values defined for this bean.
*/
default boolean hasConstructorArgumentValues() {
return !getConstructorArgumentValues().isEmpty();
}
/**
* Return the property values to be applied to a new instance of the bean.
*
The returned instance can be modified during bean factory post-processing.
*
* @return the PropertyValues object (never {@code null})
*/
PropertyValues getPropertyValues();
/**
* Return if there are property values defined for this bean.
*/
default boolean hasPropertyValues() {
return !getPropertyValues().isEmpty();
}
/**
* Set the name of the initializer method.
*/
void setInitMethodName(@Nullable String initMethodName);
/**
* Return the name of the initializer method.
*/
@Nullable
String getInitMethodName();
/**
* Set the name of the destroy method.
*/
void setDestroyMethodName(@Nullable String destroyMethodName);
/**
* Return the name of the destroy method.
*/
@Nullable
String getDestroyMethodName();
/**
* Set the role hint for this {@code BeanDefinition}. The role hint
* provides the frameworks as well as tools an indication of
* the role and importance of a particular {@code BeanDefinition}.
*
* @see #ROLE_APPLICATION
* @see #ROLE_SUPPORT
* @see #ROLE_INFRASTRUCTURE
*/
void setRole(int role);
/**
* Get the role hint for this {@code BeanDefinition}. The role hint
* provides the frameworks as well as tools an indication of
* the role and importance of a particular {@code BeanDefinition}.
*
* @see #ROLE_APPLICATION
* @see #ROLE_SUPPORT
* @see #ROLE_INFRASTRUCTURE
*/
int getRole();
/**
* Set a human-readable description of this bean definition.
*/
void setDescription(@Nullable String description);
/**
* Return a human-readable description of this bean definition.
*/
@Nullable
String getDescription();
// Read-only attributes
/**
* Return a resolvable type for this bean definition,
* based on the bean class or other specific metadata.
*
This is typically fully resolved on a runtime-merged bean definition
* but not necessarily on a configuration-time definition instance.
*
* @return the resolvable type (potentially {@link ResolvableType#NONE})
* @see ConfigurableBeanFactory#getMergedBeanDefinition
*/
ResolvableType getResolvableType();
/**
* Return whether this a Singleton, with a single, shared instance
* returned on all calls.
*
* @see #SCOPE_SINGLETON
*/
boolean isSingleton();
/**
* Return whether this a Prototype, with an independent instance
* returned for each call.
*
* @see #SCOPE_PROTOTYPE
*/
boolean isPrototype();
/**
* Return whether this bean is "abstract", that is, not meant to be instantiated.
*/
boolean isAbstract();
/** @since 4.0 */
boolean isEnableDependencyInjection();
/** @since 4.0 */
void setEnableDependencyInjection(boolean enableDependencyInjection);
/**
* Return a description of the resource that this bean definition
* came from (for the purpose of showing context in case of errors).
*/
@Nullable
String getResourceDescription();
/**
* Return the originating BeanDefinition, or {@code null} if none.
*
Allows for retrieving the decorated bean definition, if any.
*
Note that this method returns the immediate originator. Iterate through the
* originator chain to find the original BeanDefinition as defined by the user.
*/
@Nullable
BeanDefinition getOriginatingBeanDefinition();
/**
* Clone this bean definition.
* To be implemented by concrete subclasses.
*
* @return the cloned bean definition object
*/
BeanDefinition cloneBeanDefinition();
}