net.sf.jguiraffe.di

Interface BeanContext

All Known Implementing Classes:

BeanContextWrapper, DefaultBeanContext

public interface BeanContext

Definition of an interface that allows access to the beans managed by the dependency injection framework.

This interface serves as the top-level entry point into the dependency injection framework. It allows querying beans from a specified BeanStore or a default BeanStore by name or by type. Listing the available beans is also possible.

When objects are dynamically created, class loader issues have to be taken into account. A BeanContext allows the registration of class loaders by name. In the configuration, it can then be specified, which bean is to be created using which class loader. For the context class loader there is a special constant.

Version:

$Id: BeanContext.java 205 2012-01-29 18:29:57Z oheger $

Author:

Oliver Heger

Method Summary

Modifier and Type	Method and Description
void	addBeanCreationListener(BeanCreationListener l) Adds a new BeanCreationListener to this context.
Set<Class<?>>	beanClasses() Returns a set with the classes of all beans defined in the default BeanStore (or one of its parents).
Set<Class<?>>	beanClasses(BeanStore store) Returns a set with the classes of all beans defined in the given BeanStore.
String	beanNameFor(BeanProvider beanProvider) Returns the name of the bean that is managed by the specified BeanProvider, starting search with the default BeanStore.
String	beanNameFor(BeanProvider beanProvider, BeanStore store) Returns the name of the bean that is managed by the specified BeanProvider, starting search in the specified BeanStore.
Set<String>	beanNames() Returns a set with the names of all beans defined in the default BeanStore.
Set<String>	beanNames(BeanStore store) Returns a set with the names of all beans defined in the given BeanStore.
void	close() Closes this bean context.
boolean	containsBean(Class<?> beanClass) Checks whether the default BeanStore contains a bean with the given class.
boolean	containsBean(Class<?> beanClass, BeanStore store) Checks whether the specified BeanStore contains a bean with the given class.
boolean	containsBean(String name) Checks whether the default BeanStore contains a bean with the given name.
boolean	containsBean(String name, BeanStore store) Checks whether the specified BeanStore contains a bean with the given name.
<T> T	getBean(Class<T> beanCls) Returns the bean with the specified class from the default BeanStore.
<T> T	getBean(Class<T> beanCls, BeanStore store) Returns the bean with the specified class from the given BeanStore.
Object	getBean(String name) Returns the bean with the specified name from the default BeanStore.
Object	getBean(String name, BeanStore store) Returns the bean with the specified name from the given BeanStore.
ClassLoaderProvider	getClassLoaderProvider() Returns the ClassLoaderProvider used by this context.
BeanStore	getDefaultBeanStore() Returns the default bean store.
void	removeBeanCreationListener(BeanCreationListener l) Removes the specified BeanCreationListener from this context.
void	setClassLoaderProvider(ClassLoaderProvider clp) Sets the ClassLoaderProvider to be used by this context.
void	setDefaultBeanStore(BeanStore store) Sets the default bean store.

Method Detail

getBean

Object getBean(String name)

Returns the bean with the specified name from the default BeanStore.

Parameters:

name - the name of the bean to be retrieved

Returns:

the bean with this name

Throws:

InjectionException - if the bean cannot be resolved or its creation or initialization causes an error

getBean

Object getBean(String name,
               BeanStore store)

Returns the bean with the specified name from the given BeanStore. This method can be used if a child bean store of the default bean store is to be accessed.

Parameters:

name - the name of the bean to be retrieved

store - the BeanStore to query

Returns:

the bean with this name

Throws:

InjectionException - if the bean cannot be resolved or its creation or initialization causes an error

IllegalArgumentException - if the passed in bean store is null

getBean

<T> T getBean(Class<T> beanCls)

Returns the bean with the specified class from the default BeanStore. An implementation of this method has to iterate over the beans defined in the bean store to find out, whether the specified class is assignable from their class. Then the first fitting bean will be returned. So it is for instance possible to query for an interface and find a bean that is a concrete implementation of this interface. If there are multiple bean definitions that are compatible with this class, it is up to a concrete implementation of this interface to choose one. Defining beans based on a class (or interface) allows to abstract from the concrete naming of beans and focuses more on the beans' semantics.

Type Parameters:

T - the type of the bean to be fetched

Parameters:

beanCls - the class of the bean to be fetched

Returns:

the bean with this class

Throws:

InjectionException - if the bean cannot be resolved or its creation or initialization causes an error

getBean

<T> T getBean(Class<T> beanCls,
              BeanStore store)

Returns the bean with the specified class from the given BeanStore. Works like the overloaded method, but operates on the given bean store.

Type Parameters:

T - the type of the bean to be fetched

Parameters:

beanCls - the class of the bean to be fetched

store - the BeanStore to use

Returns:

the bean with this class

Throws:

InjectionException - if the bean cannot be resolved or its creation or initialization causes an error

IllegalArgumentException - if the passed in bean store is null

beanNames

Set<String> beanNames()

Returns a set with the names of all beans defined in the default BeanStore.

Returns:

a set with the names of the defined beans

beanNames

Set<String> beanNames(BeanStore store)

Returns a set with the names of all beans defined in the given BeanStore. This list will also contain beans that are defined in one of the bean store's parents.

Parameters:

store - the bean store (must not be null)

Returns:

a set with the names of the defined beans

Throws:

IllegalArgumentException - if the passed in bean store is null

beanClasses

Set<Class<?>> beanClasses()

Returns a set with the classes of all beans defined in the default BeanStore (or one of its parents).

Returns:

a set with the classes of the defined beans

beanClasses

Set<Class<?>> beanClasses(BeanStore store)

Returns a set with the classes of all beans defined in the given BeanStore. This list will also contain beans that are defined in one of the bean store's parents.

Parameters:

store - the bean store (must not be null)

Returns:

a set with the classes of the defined beans

Throws:

IllegalArgumentException - if the passed in bean store is null

containsBean

boolean containsBean(String name)

Checks whether the default BeanStore contains a bean with the given name. If necessary the bean store's parents will also be searched.

Parameters:

name - the name of the searched bean

Returns:

a flag whether this bean can be found

containsBean

boolean containsBean(String name,
                     BeanStore store)

Checks whether the specified BeanStore contains a bean with the given name. If necessary the bean store's parents will also be searched.

Parameters:

name - the name of the searched bean

store - the bean store

Returns:

a flag whether this bean can be found

containsBean

boolean containsBean(Class<?> beanClass)

Checks whether the default BeanStore contains a bean with the given class. If necessary the bean store's parents will also be searched.

Parameters:

beanClass - the class of the searched bean

Returns:

a flag whether this bean can be found

containsBean

boolean containsBean(Class<?> beanClass,
                     BeanStore store)

Checks whether the specified BeanStore contains a bean with the given class. If necessary the bean store's parents will also be searched.

Parameters:

beanClass - the class of the searched bean

store - the bean store

Returns:

a flag whether this bean can be found

getDefaultBeanStore

BeanStore getDefaultBeanStore()

Returns the default bean store.

Returns:

the default bean store

setDefaultBeanStore

void setDefaultBeanStore(BeanStore store)

Sets the default bean store. This bean store is used as starting point for all lookup-operations if no specific bean store is specified.

Parameters:

store - the new default bean store

beanNameFor

String beanNameFor(BeanProvider beanProvider)

Returns the name of the bean that is managed by the specified BeanProvider, starting search with the default BeanStore.

Parameters:

beanProvider - the BeanProvider

Returns:

the name, under which this BeanProvider is registered in one of the accessible bean stores or null if it cannot be resolved

See Also:

beanNameFor(BeanProvider, BeanStore)

beanNameFor

String beanNameFor(BeanProvider beanProvider,
                   BeanStore store)

Returns the name of the bean that is managed by the specified BeanProvider, starting search in the specified BeanStore. This method can be used for performing a "reverse lookup": when a bean provider is known, but the corresponding bean name is searched. A use case would be the processing of a BeanCreationEvent. The event object contains the BeanProvider that created the bean, but the name of this bean is not part of the event.

Parameters:

beanProvider - the BeanProvider

store - the BeanStore

Returns:

the name, under which this BeanProvider is registered in one of the accessible bean stores or null if it cannot be resolved

addBeanCreationListener

void addBeanCreationListener(BeanCreationListener l)

Adds a new BeanCreationListener to this context. This listener will receive notifications about newly created beans.

Parameters:

l - the listener to be added (must not be null)

Throws:

IllegalArgumentException - if the listener is null

removeBeanCreationListener

void removeBeanCreationListener(BeanCreationListener l)

Removes the specified BeanCreationListener from this context. If the listener is not registered, this method has no effect.

Parameters:

l - the listener to remove

close

void close()

Closes this bean context. This method should be called when the context is no more needed. An implementation can free resources or perform other clean up. Note that the BeanStore associated with this context is not closed by this method (this is because a BeanStore could be shared by multiple contexts, and there is not necessary a 1:1 relationship between a BeanStore and a BeanContext).

getClassLoaderProvider

ClassLoaderProvider getClassLoaderProvider()

Returns the ClassLoaderProvider used by this context.

Returns:

the ClassLoaderProvider

setClassLoaderProvider

void setClassLoaderProvider(ClassLoaderProvider clp)

Sets the ClassLoaderProvider to be used by this context. This object is needed when classes have to be loaded through reflection.

Parameters:

clp - the ClassLoaderProvider