net.sf.jguiraffe.di.impl.providers

Class MapBeanProvider

java.lang.Object

net.sf.jguiraffe.di.impl.providers.SimpleBeanProvider

net.sf.jguiraffe.di.impl.providers.MapBeanProvider

All Implemented Interfaces:

BeanProvider

Direct Known Subclasses:

PropertiesBeanProvider

public class MapBeanProvider
extends SimpleBeanProvider

A specialized BeanProvider implementation for creating beans of type java.util.Map.

With this bean provider implementation either a java.util.HashMap or a java.util.LinkedHashMap can be created and populated. The mechanisms used here are very similar to the ones used by CollectionBeanProvider: an instance is initialized with two lists of Dependency objects - one list represents the key, the other list represents the values of the map. The getDependencies() method returns a union of all these dependencies. When the Map bean is to be created, a new instance of the correct Map class is created. Then the dependencies for the keys and values are resolved, and the corresponding objects are added to the map.

Bean providers of this type are intended to be used together with a LifeCycleBeanProvider that controls the creation of new instances.

Implementation note: Objects of this class are immutable and thus can be shared between multiple threads.

Version:

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

Author:

Oliver Heger

Constructor Summary

Constructors

Constructor and Description
MapBeanProvider(Collection<Dependency> keyDeps, Collection<Dependency> valDeps, boolean ordered) Creates a new instance of MapBeanProvider and initializes it.

Method Summary

Modifier and Type	Method and Description
protected Map<Object,Object>	createMap() Creates the map managed by this provider.
Object	getBean(DependencyProvider dependencyProvider) Returns the bean managed by this provider.
Class<?>	getBeanClass(DependencyProvider dependencyProvider) Returns the class of the managed bean.
Set<Dependency>	getDependencies() Returns the dependencies of this bean provider.
Collection<Dependency>	getKeyDependencies() Returns the dependencies for the keys of the map.
Collection<Dependency>	getValueDependencies() Returns the dependencies for the values of the map.
boolean	isOrdered() Returns the ordered flag.

Methods inherited from class net.sf.jguiraffe.di.impl.providers.SimpleBeanProvider

getLockID, isBeanAvailable, setLockID, shutdown

Methods inherited from class java.lang.Object

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

Constructor Detail

MapBeanProvider

public MapBeanProvider(Collection<Dependency> keyDeps,
                       Collection<Dependency> valDeps,
                       boolean ordered)

Creates a new instance of MapBeanProvider and initializes it.

Parameters:

keyDeps - the dependencies for the keys of the map (must not be null)

valDeps - the dependencies for the values of the map (must not be null)

ordered - a flag whether the order of the dependencies should be maintained

Throws:

IllegalArgumentException - if either keyDeps or valDeps is null or the sizes of the collections are different

Method Detail

getKeyDependencies

public Collection<Dependency> getKeyDependencies()

Returns the dependencies for the keys of the map.

Returns:

the key dependencies

getValueDependencies

public Collection<Dependency> getValueDependencies()

Returns the dependencies for the values of the map.

Returns:

the value dependencies

isOrdered

public boolean isOrdered()

Returns the ordered flag. This property determines the type of the map created by this provider.

Returns:

the ordered flag

getBean

public Object getBean(DependencyProvider dependencyProvider)

Returns the bean managed by this provider. This implementation calls createMap() to create the map. Then the dependencies for keys and values are resolved and added to the map.

Parameters:

dependencyProvider - the dependency provider

Returns:

the managed bean

getBeanClass

public Class<?> getBeanClass(DependencyProvider dependencyProvider)

Returns the class of the managed bean. This implementation simply returns the unspecific java.util.Map class.

Parameters:

dependencyProvider - the dependency provider

Returns:

the class of the bean managed by this provider

getDependencies

public Set<Dependency> getDependencies()

Returns the dependencies of this bean provider. This implementation returns a union of all key and value dependencies.

Specified by:

getDependencies in interface BeanProvider

Overrides:

getDependencies in class SimpleBeanProvider

Returns:

a set with all dependencies of this bean provider

See Also:

Dependency

createMap

protected Map<Object,Object> createMap()

Creates the map managed by this provider. This implementation checks the ordered property and either creates a hash map or a linked hash map.

Returns:

the map