org.springframework.beans.factory.config

类 AbstractFactoryBean<T>

java.lang.Object

org.springframework.beans.factory.config.AbstractFactoryBean<T>

所有已实现的接口:

Aware, BeanClassLoaderAware, BeanFactoryAware, DisposableBean, FactoryBean<T>, InitializingBean

直接已知子类:

AbstractServiceLoaderBasedFactoryBean, ListFactoryBean, MapFactoryBean, ObjectFactoryCreatingFactoryBean, ProviderCreatingFactoryBean, SetFactoryBean

public abstract class AbstractFactoryBean<T>
extends Object
implements FactoryBean<T>, BeanClassLoaderAware, BeanFactoryAware, InitializingBean, DisposableBean

Simple template superclass for FactoryBean implementations that creates a singleton or a prototype object, depending on a flag.

If the "singleton" flag is true (the default), this class will create the object that it creates exactly once on initialization and subsequently return said singleton instance on all calls to the getObject() method.

Else, this class will create a new instance every time the getObject() method is invoked. Subclasses are responsible for implementing the abstract createInstance() template method to actually create the object(s) to expose.

从以下版本开始:

1.0.2

作者:

Juergen Hoeller, Keith Donald

另请参阅:

setSingleton(boolean), createInstance()

字段概要

字段

限定符和类型	字段和说明
protected Log	logger Logger available to subclasses

构造器概要

构造器

构造器和说明
AbstractFactoryBean()

方法概要

限定符和类型	方法和说明
void	afterPropertiesSet() Eagerly create the singleton instance, if necessary.
protected abstract T	createInstance() Template method that subclasses must override to construct the object returned by this factory.
void	destroy() Destroy the singleton instance, if any.
protected void	destroyInstance(T instance) Callback for destroying a singleton instance.
protected BeanFactory	getBeanFactory() Return the BeanFactory that this bean runs in.
protected TypeConverter	getBeanTypeConverter() Obtain a bean type converter from the BeanFactory that this bean runs in.
protected Class<?>[]	getEarlySingletonInterfaces() Return an array of interfaces that a singleton object exposed by this FactoryBean is supposed to implement, for use with an 'early singleton proxy' that will be exposed in case of a circular reference.
T	getObject() Expose the singleton instance or create a new prototype instance.
abstract Class<?>	getObjectType() This abstract method declaration mirrors the method in the FactoryBean interface, for a consistent offering of abstract template methods.
boolean	isSingleton() Is the object managed by this factory a singleton?
void	setBeanClassLoader(ClassLoader classLoader) Callback that supplies the bean class loader to a bean instance.
void	setBeanFactory(BeanFactory beanFactory) Callback that supplies the owning factory to a bean instance.
void	setSingleton(boolean singleton) Set if a singleton should be created, or a new object on each request otherwise.

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

字段详细资料

logger

protected final Log logger

Logger available to subclasses

构造器详细资料

AbstractFactoryBean

public AbstractFactoryBean()

方法详细资料

setSingleton

public void setSingleton(boolean singleton)

Set if a singleton should be created, or a new object on each request otherwise. Default is true (a singleton).

isSingleton

public boolean isSingleton()

从接口复制的说明: FactoryBean

Is the object managed by this factory a singleton? That is, will FactoryBean.getObject() always return the same object (a reference that can be cached)?

NOTE: If a FactoryBean indicates to hold a singleton object, the object returned from getObject() might get cached by the owning BeanFactory. Hence, do not return true unless the FactoryBean always exposes the same reference.

The singleton status of the FactoryBean itself will generally be provided by the owning BeanFactory; usually, it has to be defined as singleton there.

NOTE: This method returning false does not necessarily indicate that returned objects are independent instances. An implementation of the extended SmartFactoryBean interface may explicitly indicate independent instances through its SmartFactoryBean.isPrototype() method. Plain FactoryBean implementations which do not implement this extended interface are simply assumed to always return independent instances if the isSingleton() implementation returns false.

The default implementation returns true, since a FactoryBean typically manages a singleton instance.

指定者:

isSingleton 在接口中 FactoryBean<T>

返回:

whether the exposed object is a singleton

另请参阅:

FactoryBean.getObject(), SmartFactoryBean.isPrototype()

setBeanClassLoader

public void setBeanClassLoader(ClassLoader classLoader)

从接口复制的说明: BeanClassLoaderAware

Callback that supplies the bean class loader to a bean instance.

Invoked after the population of normal bean properties but before an initialization callback such as InitializingBean's InitializingBean.afterPropertiesSet() method or a custom init-method.

指定者:

setBeanClassLoader 在接口中 BeanClassLoaderAware

参数:

classLoader - the owning class loader

setBeanFactory

public void setBeanFactory(@Nullable
                           BeanFactory beanFactory)

从接口复制的说明: BeanFactoryAware

Callback that supplies the owning factory to a bean instance.

Invoked after the population of normal bean properties but before an initialization callback such as InitializingBean.afterPropertiesSet() or a custom init-method.

指定者:

setBeanFactory 在接口中 BeanFactoryAware

参数:

beanFactory - owning BeanFactory (never null). The bean can immediately call methods on the factory.

另请参阅:

BeanInitializationException

getBeanFactory

@Nullable
protected BeanFactory getBeanFactory()

Return the BeanFactory that this bean runs in.

getBeanTypeConverter

protected TypeConverter getBeanTypeConverter()

Obtain a bean type converter from the BeanFactory that this bean runs in. This is typically a fresh instance for each call, since TypeConverters are usually not thread-safe.

Falls back to a SimpleTypeConverter when not running in a BeanFactory.

另请参阅:

ConfigurableBeanFactory.getTypeConverter(), SimpleTypeConverter

afterPropertiesSet

public void afterPropertiesSet()
                        throws Exception

Eagerly create the singleton instance, if necessary.

指定者:

afterPropertiesSet 在接口中 InitializingBean

抛出:

Exception - in the event of misconfiguration (such as failure to set an essential property) or if initialization fails for any other reason

getObject

public final T getObject()
                  throws Exception

Expose the singleton instance or create a new prototype instance.

指定者:

getObject 在接口中 FactoryBean<T>

返回:

an instance of the bean (can be null)

抛出:

Exception - in case of creation errors

另请参阅:

createInstance(), getEarlySingletonInterfaces()

destroy

public void destroy()
             throws Exception

Destroy the singleton instance, if any.

指定者:

destroy 在接口中 DisposableBean

抛出:

Exception - in case of shutdown errors. Exceptions will get logged but not rethrown to allow other beans to release their resources as well.

另请参阅:

destroyInstance(Object)

getObjectType

@Nullable
public abstract Class<?> getObjectType()

This abstract method declaration mirrors the method in the FactoryBean interface, for a consistent offering of abstract template methods.

指定者:

getObjectType 在接口中 FactoryBean<T>

返回:

the type of object that this FactoryBean creates, or null if not known at the time of the call

另请参阅:

FactoryBean.getObjectType()

createInstance

protected abstract T createInstance()
                             throws Exception

Template method that subclasses must override to construct the object returned by this factory.

Invoked on initialization of this FactoryBean in case of a singleton; else, on each getObject() call.

返回:

the object returned by this factory

抛出:

Exception - if an exception occurred during object creation

另请参阅:

getObject()

getEarlySingletonInterfaces

@Nullable
protected Class<?>[] getEarlySingletonInterfaces()

Return an array of interfaces that a singleton object exposed by this FactoryBean is supposed to implement, for use with an 'early singleton proxy' that will be exposed in case of a circular reference.

The default implementation returns this FactoryBean's object type, provided that it is an interface, or null otherwise. The latter indicates that early singleton access is not supported by this FactoryBean. This will lead to a FactoryBeanNotInitializedException getting thrown.

返回:

the interfaces to use for 'early singletons', or null to indicate a FactoryBeanNotInitializedException

另请参阅:

FactoryBeanNotInitializedException

destroyInstance

protected void destroyInstance(@Nullable
                               T instance)
                        throws Exception

Callback for destroying a singleton instance. Subclasses may override this to destroy the previously created instance.

The default implementation is empty.

参数:

instance - the singleton instance, as returned by createInstance()

抛出:

Exception - in case of shutdown errors

另请参阅:

createInstance()