org.picocontainer.adapters

Class NullCA

java.lang.Object

org.picocontainer.adapters.NullCA

All Implemented Interfaces:

ComponentAdapter

public class NullCA
extends Object
implements ComponentAdapter

Nested Class Summary

Nested classes/interfaces inherited from interface org.picocontainer.ComponentAdapter

ComponentAdapter.NOTHING

Constructor Summary

Constructors

Constructor and Description
NullCA(Object key)

Method Summary

Modifier and Type	Method and Description
void	accept(PicoVisitor visitor) Accepts a visitor for this ComponentAdapter.
ComponentAdapter	findAdapterOfType(Class adapterType) Locates a component adapter of type componentAdapterType in the ComponentAdapter chain.
Class	getComponentImplementation() Retrieve the class of the component.
Object	getComponentInstance(PicoContainer container) Retrieve the component instance.
Object	getComponentInstance(PicoContainer container, Type into) Retrieve the component instance.
Object	getComponentKey() Retrieve the key associated with the component.
ComponentAdapter	getDelegate() Component adapters may be nested in a chain, and this method is used to grab the next ComponentAdapter in the chain.
String	getDescriptor() Get a string key descriptor of the component adapter for use in toString()
void	verify(PicoContainer container) Verify that all dependencies for this adapter can be satisfied.

Methods inherited from class java.lang.Object

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

Constructor Detail

NullCA

public NullCA(Object key)

Method Detail

getComponentKey

public Object getComponentKey()

Description copied from interface: ComponentAdapter

Retrieve the key associated with the component.

Specified by:

getComponentKey in interface ComponentAdapter

Returns:

the component's key. Should either be a class type (normally an interface) or an identifier that is unique (within the scope of the current PicoContainer).

getComponentImplementation

public Class getComponentImplementation()

Description copied from interface: ComponentAdapter

Retrieve the class of the component.

Specified by:

getComponentImplementation in interface ComponentAdapter

Returns:

the component's implementation class. Should normally be a concrete class (ie, a class that can be instantiated).

getComponentInstance

public Object getComponentInstance(PicoContainer container)

Description copied from interface: ComponentAdapter

Retrieve the component instance. This method will usually create a new instance each time it is called, but that is not required. For example, Cached will always return the same instance.

Specified by:

getComponentInstance in interface ComponentAdapter

Parameters:

container - the PicoContainer, that is used to resolve any possible dependencies of the instance.

Returns:

the component instance.

getComponentInstance

public Object getComponentInstance(PicoContainer container,
                                   Type into)

Description copied from interface: ComponentAdapter

Retrieve the component instance. This method will usually create a new instance each time it is called, but that is not required. For example, Cached will always return the same instance.

Specified by:

getComponentInstance in interface ComponentAdapter

Parameters:

container - the PicoContainer, that is used to resolve any possible dependencies of the instance.

into - the class that is about to be injected into. Use ComponentAdapter.NOTHING.class if this is not important to you.

Returns:

the component instance.

verify

public void verify(PicoContainer container)

Description copied from interface: ComponentAdapter

Verify that all dependencies for this adapter can be satisfied. Normally, the adapter should verify this by checking that the associated PicoContainer contains all the needed dependencies.

Specified by:

verify in interface ComponentAdapter

Parameters:

container - the PicoContainer, that is used to resolve any possible dependencies of the instance.

accept

public void accept(PicoVisitor visitor)

Description copied from interface: ComponentAdapter

Accepts a visitor for this ComponentAdapter. The method is normally called by visiting a PicoContainer, that cascades the visitor also down to all its ComponentAdapter instances.

Specified by:

accept in interface ComponentAdapter

Parameters:

visitor - the visitor.

getDelegate

public ComponentAdapter getDelegate()

Description copied from interface: ComponentAdapter

Component adapters may be nested in a chain, and this method is used to grab the next ComponentAdapter in the chain.

Specified by:

getDelegate in interface ComponentAdapter

Returns:

the next component adapter in line or null if there is no delegate ComponentAdapter.

findAdapterOfType

public ComponentAdapter findAdapterOfType(Class adapterType)

Description copied from interface: ComponentAdapter

Locates a component adapter of type componentAdapterType in the ComponentAdapter chain. Will return null if there is no adapter of the given type.

Specified by:

findAdapterOfType in interface ComponentAdapter

Parameters:

adapterType - the class of the adapter type being located. Never null.

Returns:

the appropriate component adapter of type U. May return null if the component adapter type is not returned.

getDescriptor

public String getDescriptor()

Description copied from interface: ComponentAdapter

Get a string key descriptor of the component adapter for use in toString()

Specified by:

getDescriptor in interface ComponentAdapter

Returns:

the descriptor