Class DefaultSingletonBeanRegistry
- All Implemented Interfaces:
SingletonBeanRegistry
,AliasRegistry
- Direct Known Subclasses:
FactoryBeanRegistrySupport
SingletonBeanRegistry
.
Allows for registering singleton instances that should be shared
for all callers of the registry, to be obtained via bean name.
Also supports registration of
DisposableBean
instances,
(which might or might not correspond to registered singletons),
to be destroyed on shutdown of the registry. Dependencies between
beans can be registered to enforce an appropriate shutdown order.
This class mainly serves as base class for
BeanFactory
implementations,
factoring out the common management of singleton bean instances. Note that
the ConfigurableBeanFactory
interface extends the SingletonBeanRegistry
interface.
Note that this class assumes neither a bean definition concept
nor a specific creation process for bean instances, in contrast to
AbstractBeanFactory
and DefaultListableBeanFactory
(which inherit from it). Can alternatively also be used as a nested
helper to delegate to.
- Since:
- 2.0
- Author:
- Juergen Hoeller
- See Also:
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Field Summary
Fields inherited from class org.springframework.core.SimpleAliasRegistry
logger
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionprotected void
addSingleton
(String beanName, Object singletonObject) Add the given singleton object to the singleton cache of this factory.protected void
addSingletonFactory
(String beanName, ObjectFactory<?> singletonFactory) Add the given singleton factory for building the specified singleton if necessary.protected void
afterSingletonCreation
(String beanName) Callback after singleton creation.protected void
beforeSingletonCreation
(String beanName) Callback before singleton creation.protected void
Clear all cached singleton instances in this registry.boolean
containsSingleton
(String beanName) Check if this registry contains a singleton instance with the given name.protected void
destroyBean
(String beanName, DisposableBean bean) Destroy the given bean.void
destroySingleton
(String beanName) Destroy the given bean.void
String[]
getDependenciesForBean
(String beanName) Return the names of all beans that the specified bean depends on, if any.String[]
getDependentBeans
(String beanName) Return the names of all beans which depend on the specified bean, if any.getSingleton
(String beanName) Return the (raw) singleton object registered under the given name.protected Object
getSingleton
(String beanName, boolean allowEarlyReference) Return the (raw) singleton object registered under the given name.getSingleton
(String beanName, ObjectFactory<?> singletonFactory) Return the (raw) singleton object registered under the given name, creating and registering a new one if none registered yet.int
Return the number of singleton beans registered in this registry.final Object
Exposes the singleton mutex to subclasses and external collaborators.String[]
Return the names of singleton beans registered in this registry.protected boolean
hasDependentBean
(String beanName) Determine whether a dependent bean has been registered for the given name.protected boolean
isActuallyInCreation
(String beanName) boolean
isCurrentlyInCreation
(String beanName) protected boolean
isDependent
(String beanName, String dependentBeanName) Determine whether the specified dependent bean has been registered as dependent on the given bean or on any of its transitive dependencies.boolean
isSingletonCurrentlyInCreation
(String beanName) Return whether the specified singleton bean is currently in creation (within the entire factory).protected void
Register an exception that happened to get suppressed during the creation of a singleton bean instance, e.g.void
registerContainedBean
(String containedBeanName, String containingBeanName) Register a containment relationship between two beans, e.g.void
registerDependentBean
(String beanName, String dependentBeanName) Register a dependent bean for the given bean, to be destroyed before the given bean is destroyed.void
registerDisposableBean
(String beanName, DisposableBean bean) Add the given bean to the list of disposable beans in this registry.void
registerSingleton
(String beanName, Object singletonObject) Register the given existing object as singleton in the bean registry, under the given bean name.protected void
removeSingleton
(String beanName) Remove the bean with the given name from the singleton cache of this factory, to be able to clean up eager registration of a singleton if creation failed.void
setCurrentlyInCreation
(String beanName, boolean inCreation) Methods inherited from class org.springframework.core.SimpleAliasRegistry
allowAliasOverriding, canonicalName, checkForAliasCircle, getAliases, hasAlias, isAlias, registerAlias, removeAlias, resolveAliases
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Constructor Details
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DefaultSingletonBeanRegistry
public DefaultSingletonBeanRegistry()
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Method Details
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registerSingleton
Description copied from interface:SingletonBeanRegistry
Register the given existing object as singleton in the bean registry, under the given bean name.The given instance is supposed to be fully initialized; the registry will not perform any initialization callbacks (in particular, it won't call InitializingBean's
afterPropertiesSet
method). The given instance will not receive any destruction callbacks (like DisposableBean'sdestroy
method) either.When running within a full BeanFactory: Register a bean definition instead of an existing instance if your bean is supposed to receive initialization and/or destruction callbacks.
Typically invoked during registry configuration, but can also be used for runtime registration of singletons. As a consequence, a registry implementation should synchronize singleton access; it will have to do this anyway if it supports a BeanFactory's lazy initialization of singletons.
- Specified by:
registerSingleton
in interfaceSingletonBeanRegistry
- Parameters:
beanName
- the name of the beansingletonObject
- the existing singleton object- Throws:
IllegalStateException
- See Also:
-
addSingleton
Add the given singleton object to the singleton cache of this factory.To be called for eager registration of singletons.
- Parameters:
beanName
- the name of the beansingletonObject
- the singleton object
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addSingletonFactory
Add the given singleton factory for building the specified singleton if necessary.To be called for eager registration of singletons, e.g. to be able to resolve circular references.
- Parameters:
beanName
- the name of the beansingletonFactory
- the factory for the singleton object
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getSingleton
Description copied from interface:SingletonBeanRegistry
Return the (raw) singleton object registered under the given name.Only checks already instantiated singletons; does not return an Object for singleton bean definitions which have not been instantiated yet.
The main purpose of this method is to access manually registered singletons (see
SingletonBeanRegistry.registerSingleton(java.lang.String, java.lang.Object)
). Can also be used to access a singleton defined by a bean definition that already been created, in a raw fashion.NOTE: This lookup method is not aware of FactoryBean prefixes or aliases. You need to resolve the canonical bean name first before obtaining the singleton instance.
- Specified by:
getSingleton
in interfaceSingletonBeanRegistry
- Parameters:
beanName
- the name of the bean to look for- Returns:
- the registered singleton object, or
null
if none found - See Also:
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getSingleton
Return the (raw) singleton object registered under the given name.Checks already instantiated singletons and also allows for an early reference to a currently created singleton (resolving a circular reference).
- Parameters:
beanName
- the name of the bean to look forallowEarlyReference
- whether early references should be created or not- Returns:
- the registered singleton object, or
null
if none found
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getSingleton
Return the (raw) singleton object registered under the given name, creating and registering a new one if none registered yet.- Parameters:
beanName
- the name of the beansingletonFactory
- the ObjectFactory to lazily create the singleton with, if necessary- Returns:
- the registered singleton object
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onSuppressedException
Register an exception that happened to get suppressed during the creation of a singleton bean instance, e.g. a temporary circular reference resolution problem.The default implementation preserves any given exception in this registry's collection of suppressed exceptions, up to a limit of 100 exceptions, adding them as related causes to an eventual top-level
BeanCreationException
.- Parameters:
ex
- the Exception to register- See Also:
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removeSingleton
Remove the bean with the given name from the singleton cache of this factory, to be able to clean up eager registration of a singleton if creation failed.- Parameters:
beanName
- the name of the bean- See Also:
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containsSingleton
Description copied from interface:SingletonBeanRegistry
Check if this registry contains a singleton instance with the given name.Only checks already instantiated singletons; does not return
true
for singleton bean definitions which have not been instantiated yet.The main purpose of this method is to check manually registered singletons (see
SingletonBeanRegistry.registerSingleton(java.lang.String, java.lang.Object)
). Can also be used to check whether a singleton defined by a bean definition has already been created.To check whether a bean factory contains a bean definition with a given name, use ListableBeanFactory's
containsBeanDefinition
. Calling bothcontainsBeanDefinition
andcontainsSingleton
answers whether a specific bean factory contains a local bean instance with the given name.Use BeanFactory's
containsBean
for general checks whether the factory knows about a bean with a given name (whether manually registered singleton instance or created by bean definition), also checking ancestor factories.NOTE: This lookup method is not aware of FactoryBean prefixes or aliases. You need to resolve the canonical bean name first before checking the singleton status.
- Specified by:
containsSingleton
in interfaceSingletonBeanRegistry
- Parameters:
beanName
- the name of the bean to look for- Returns:
- if this bean factory contains a singleton instance with the given name
- See Also:
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getSingletonNames
Description copied from interface:SingletonBeanRegistry
Return the names of singleton beans registered in this registry.Only checks already instantiated singletons; does not return names for singleton bean definitions which have not been instantiated yet.
The main purpose of this method is to check manually registered singletons (see
SingletonBeanRegistry.registerSingleton(java.lang.String, java.lang.Object)
). Can also be used to check which singletons defined by a bean definition have already been created.- Specified by:
getSingletonNames
in interfaceSingletonBeanRegistry
- Returns:
- the list of names as a String array (never
null
) - See Also:
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getSingletonCount
public int getSingletonCount()Description copied from interface:SingletonBeanRegistry
Return the number of singleton beans registered in this registry.Only checks already instantiated singletons; does not count singleton bean definitions which have not been instantiated yet.
The main purpose of this method is to check manually registered singletons (see
SingletonBeanRegistry.registerSingleton(java.lang.String, java.lang.Object)
). Can also be used to count the number of singletons defined by a bean definition that have already been created.- Specified by:
getSingletonCount
in interfaceSingletonBeanRegistry
- Returns:
- the number of singleton beans
- See Also:
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setCurrentlyInCreation
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isCurrentlyInCreation
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isActuallyInCreation
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isSingletonCurrentlyInCreation
Return whether the specified singleton bean is currently in creation (within the entire factory).- Parameters:
beanName
- the name of the bean
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beforeSingletonCreation
Callback before singleton creation.The default implementation register the singleton as currently in creation.
- Parameters:
beanName
- the name of the singleton about to be created- See Also:
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afterSingletonCreation
Callback after singleton creation.The default implementation marks the singleton as not in creation anymore.
- Parameters:
beanName
- the name of the singleton that has been created- See Also:
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registerDisposableBean
Add the given bean to the list of disposable beans in this registry.Disposable beans usually correspond to registered singletons, matching the bean name but potentially being a different instance (for example, a DisposableBean adapter for a singleton that does not naturally implement Spring's DisposableBean interface).
- Parameters:
beanName
- the name of the beanbean
- the bean instance
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registerContainedBean
Register a containment relationship between two beans, e.g. between an inner bean and its containing outer bean.Also registers the containing bean as dependent on the contained bean in terms of destruction order.
- Parameters:
containedBeanName
- the name of the contained (inner) beancontainingBeanName
- the name of the containing (outer) bean- See Also:
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registerDependentBean
Register a dependent bean for the given bean, to be destroyed before the given bean is destroyed.- Parameters:
beanName
- the name of the beandependentBeanName
- the name of the dependent bean
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isDependent
Determine whether the specified dependent bean has been registered as dependent on the given bean or on any of its transitive dependencies.- Parameters:
beanName
- the name of the bean to checkdependentBeanName
- the name of the dependent bean- Since:
- 4.0
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hasDependentBean
Determine whether a dependent bean has been registered for the given name.- Parameters:
beanName
- the name of the bean to check
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getDependentBeans
Return the names of all beans which depend on the specified bean, if any.- Parameters:
beanName
- the name of the bean- Returns:
- the array of dependent bean names, or an empty array if none
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getDependenciesForBean
Return the names of all beans that the specified bean depends on, if any.- Parameters:
beanName
- the name of the bean- Returns:
- the array of names of beans which the bean depends on, or an empty array if none
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destroySingletons
public void destroySingletons() -
clearSingletonCache
protected void clearSingletonCache()Clear all cached singleton instances in this registry.- Since:
- 4.3.15
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destroySingleton
Destroy the given bean. Delegates todestroyBean
if a corresponding disposable bean instance is found.- Parameters:
beanName
- the name of the bean- See Also:
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destroyBean
Destroy the given bean. Must destroy beans that depend on the given bean before the bean itself. Should not throw any exceptions.- Parameters:
beanName
- the name of the beanbean
- the bean instance to destroy
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getSingletonMutex
Exposes the singleton mutex to subclasses and external collaborators.Subclasses should synchronize on the given Object if they perform any sort of extended singleton creation phase. In particular, subclasses should not have their own mutexes involved in singleton creation, to avoid the potential for deadlocks in lazy-init situations.
- Specified by:
getSingletonMutex
in interfaceSingletonBeanRegistry
- Returns:
- the mutex object (never
null
)
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