net.sf.jguiraffe.di.impl
Class SimpleBeanStoreImpl

java.lang.Object
  net.sf.jguiraffe.di.impl.SimpleBeanStoreImpl

All Implemented Interfaces:

BeanStore

public class SimpleBeanStoreImpl
extends java.lang.Object
implements BeanStore

A helper class that simplifies implementations of the BeanStore interface.

The purpose of this class is to support BeanStore implementations based on classes that are not aware of BeanProviders, but provide a map-like interface for accessing their data. This is achieved in the following ways:

• Static data (in form of arbitrary objects) can directly be added to this class. Internally ConstantBeanProvider objects are created for the data objects to be managed. These providers are directly exposed through the BeanStore methods.
• If dynamic data is involved (i.e. objects that may change over time and cannot be kept in a map), components can implement the internal BeanContributor interface and register themselves at a SimpleBeanStoreImpl instance. The BeanConstributor interface is much easier to implement than the BeanStore interface. The implementations of the BeanStore methods provided by this class take the registered BeanContributors into account.
• Methods of the BeanStore interface that do not directly deal with bean providers are already implemented by this class.

Note: The class per se is not thread-safe. When used inside the dependency injection framework, proper synchronization is automatically applied. But during initialization or for other use cases the developer has to ensure that there are no concurrent accesses.

Version:

$Id: SimpleBeanStoreImpl.java 168 2009-09-11 20:12:19Z oheger $

Author:

Oliver Heger

Nested Class Summary

static interface

SimpleBeanStoreImpl.BeanContributor Definition of an interface for objects that can contribute beans for a SimpleBeanStoreImpl object.

Constructor Summary

SimpleBeanStoreImpl()
Creates a new instance of SimpleBeanStoreImpl.

SimpleBeanStoreImpl(java.lang.String name, BeanStore parent)
Creates a new instance of SimpleBeanStoreImpl and sets the name and the reference to the parent.

Method Summary

void	addBean(java.lang.String name, java.lang.Object bean) Adds the specified bean to this store.
void	addBeanContributor(SimpleBeanStoreImpl.BeanContributor contr) Adds a new BeanContributor to this object.
BeanProvider	getBeanProvider(java.lang.String name) Returns a BeanProvider for the bean with the given name.
java.lang.String	getName() Returns the name of this bean store.
BeanStore	getParent() Returns the parent bean store.
protected BeanProvider	providerFor(java.lang.Object bean) Returns a bean provider for the specified bean.
java.util.Set<java.lang.String>	providerNames() Returns a set with the names of the available bean providers.
java.lang.Object	removeBean(java.lang.String name) Removes the bean with the given name.
void	removeBeanContributor(SimpleBeanStoreImpl.BeanContributor contr) Removes the specified bean contributor from this object.
void	setName(java.lang.String name) Sets the name of this bean store.
void	setParent(BeanStore parent) Sets the parent bean store.

Methods inherited from class java.lang.Object

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

Constructor Detail

SimpleBeanStoreImpl

public SimpleBeanStoreImpl()

Creates a new instance of SimpleBeanStoreImpl.

SimpleBeanStoreImpl

public SimpleBeanStoreImpl(java.lang.String name,
                           BeanStore parent)

Creates a new instance of SimpleBeanStoreImpl and sets the name and the reference to the parent.

Parameters:

name - the name of this bean store

parent - the reference to the parent bean store

Method Detail

addBeanContributor

public void addBeanContributor(SimpleBeanStoreImpl.BeanContributor contr)

Adds a new BeanContributor to this object. This contributor will be triggered when this bean store is accessed.

Parameters:

contr - the contributor to be added (must not be null)

Throws:

java.lang.IllegalArgumentException - if the contributor is null

removeBeanContributor

public void removeBeanContributor(SimpleBeanStoreImpl.BeanContributor contr)

Removes the specified bean contributor from this object.

Parameters:

contr - the contributor to remove

addBean

public void addBean(java.lang.String name,
                    java.lang.Object bean)

Adds the specified bean to this store. For the passed in bean a constant bean provider is created. It can then be queried through the getBeanProvider() method.

Parameters:

name - the name of the bean (must not be null)

bean - the bean (must not be null)

Throws:

java.lang.IllegalArgumentException - if the name or the bean is null

removeBean

public java.lang.Object removeBean(java.lang.String name)

Removes the bean with the given name.

Parameters:

name - the name of the bean to be removed

Returns:

the removed bean (null if the bean was unknown)

getBeanProvider

public BeanProvider getBeanProvider(java.lang.String name)

Returns a BeanProvider for the bean with the given name. This implementation checks whether such a bean was directly added using the addBean() method. If not, the registered bean contributors are consulted. If no such bean can be found, null is returned.

Specified by:

getBeanProvider in interface BeanStore

Parameters:

name - the name of the bean in question

Returns:

a BeanProvider for this bean

getName

public java.lang.String getName()

Returns the name of this bean store.

Specified by:

getName in interface BeanStore

Returns:

the name of this bean store

setName

public void setName(java.lang.String name)

Sets the name of this bean store.

Parameters:

name - the new name

getParent

public BeanStore getParent()

Returns the parent bean store.

Specified by:

getParent in interface BeanStore

Returns:

the parent store

setParent

public void setParent(BeanStore parent)

Sets the parent bean store.

Parameters:

parent - the parent bean store

providerNames

public java.util.Set<java.lang.String> providerNames()

Returns a set with the names of the available bean providers. This implementation will first obtain the names of all directly added beans. Then the registered bean contributors are invoked to add their bean names to the resulting list.

Specified by:

providerNames in interface BeanStore

Returns:

a set with the names of the known bean providers

providerFor

protected BeanProvider providerFor(java.lang.Object bean)

Returns a bean provider for the specified bean. This method is called whenever a bean has to be wrapped by a provider. This default implementation returns a ConstantBeanProvider for the passed in bean.

Parameters:

bean - the bean

Returns:

a provider for this bean