Package net.shibboleth.shared.spring.factory

Class AbstractFactoryBean<T>

java.lang.Object
net.shibboleth.shared.spring.factory.AbstractFactoryBean<T>
Type Parameters:
T - the bean type
All Implemented Interfaces:
Aware, BeanClassLoaderAware, BeanFactoryAware, DisposableBean, FactoryBean<T>, InitializingBean
Direct Known Subclasses:
AbstractComponentAwareFactoryBean, ViewResolversFactoryBean
public abstract class AbstractFactoryBean<T> extends Object implements FactoryBean<T>, BeanClassLoaderAware, BeanFactoryAware, InitializingBean, DisposableBean
Cloned from Spring's base class to fix bug they won't acknowledge regarding the ability for createInstance() to return null.

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.

Since:
9.1.0
See Also:

  • Field Details

    • singleton

      private boolean singleton

    • beanClassLoader

      @Nullable private ClassLoader beanClassLoader

    • beanFactory

      @Nullable private BeanFactory beanFactory

    • initialized

      private boolean initialized

    • singletonInstance

      @Nullable private T singletonInstance

    • earlySingletonInstance

      @Nullable private T earlySingletonInstance

  • Constructor Details

    • AbstractFactoryBean

      public AbstractFactoryBean()

  • Method Details

    • 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).
      Parameters:
      singleton - flag to set

    • isSingleton

      public boolean isSingleton()
      Specified by:
      isSingleton in interface FactoryBean<T>

    • setBeanClassLoader

      public void setBeanClassLoader(@Nonnull ClassLoader classLoader)
      Specified by:
      setBeanClassLoader in interface BeanClassLoaderAware

    • setBeanFactory

      public void setBeanFactory(@Nullable BeanFactory beanFactory)
      Specified by:
      setBeanFactory in interface BeanFactoryAware

    • getBeanFactory

      @Nullable protected BeanFactory getBeanFactory()
      Return the BeanFactory that this bean runs in.
      Returns:
      bean factory

    • getBeanTypeConverter

      @Nonnull 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.

      Returns:
      type converter
      See Also:

    • afterPropertiesSet

      public void afterPropertiesSet() throws Exception
      Eagerly create the singleton instance, if necessary.
      Specified by:
      afterPropertiesSet in interface InitializingBean
      Throws:
      Exception

    • getObject

      @Nullable public final T getObject() throws Exception
      Expose the singleton instance or create a new prototype instance.
      Specified by:
      getObject in interface FactoryBean<T>
      Throws:
      Exception
      See Also:

    • getEarlySingletonInstance

      @Nullable private T getEarlySingletonInstance() throws Exception
      Determine an 'early singleton' instance, exposed in case of a circular reference. Not called in a non-circular scenario.
      Returns:
      early singleton
      Throws:
      Exception - on error

    • getSingletonInstance

      @Nullable private T getSingletonInstance() throws IllegalStateException
      Expose the singleton instance (for access through the 'early singleton' proxy).
      Returns:
      the singleton instance that this FactoryBean holds
      Throws:
      IllegalStateException - if the singleton instance is not initialized

    • destroy

      public void destroy() throws Exception
      Destroy the singleton instance, if any.
      Specified by:
      destroy in interface DisposableBean
      Throws:
      Exception
      See Also:

    • 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.
      Specified by:
      getObjectType in interface FactoryBean<T>
      See Also:

    • createInstance

      @Nullable 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.

      Returns:
      the object returned by this factory
      Throws:
      Exception - if an exception occurred during object creation
      See Also:

    • 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.

      Returns:
      the interfaces to use for 'early singletons', or null to indicate a FactoryBeanNotInitializedException
      See Also:

    • 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.

      Parameters:
      instance - the singleton instance, as returned by createInstance()
      Throws:
      Exception - in case of shutdown errors
      See Also: