org.picocontainer.injectors
Class ProviderAdapter

java.lang.Object
  org.picocontainer.injectors.ProviderAdapter

All Implemented Interfaces:

ComponentAdapter, Injector, Provider

public class ProviderAdapter
extends Object
implements Injector, Provider

Providers are a type of Injector that can participate in Injection via a custom method. Implementors of this class must implement a single method called provide. That method must return the component type intended to be provided. The method can accept parameters that PicoContainer will satisfy.

Nested Class Summary

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

ComponentAdapter.NOTHING

Constructor Summary

protected	ProviderAdapter()
	ProviderAdapter(Object provider)
	ProviderAdapter(Object provider, boolean useNames)

Method Summary

void	accept(PicoVisitor visitor) Accepts a visitor for this ComponentAdapter.
Object	decorateComponentInstance(PicoContainer container, Type into, Object instance) A preexiting component instance can be injected into after instantiation
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) Deprecated.
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.
static Method	getProvideMethod(Class clazz)
protected boolean	useNames()
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

ProviderAdapter

protected ProviderAdapter()

ProviderAdapter

public ProviderAdapter(Object provider)

ProviderAdapter

public ProviderAdapter(Object provider,
                       boolean useNames)

Method Detail

useNames

protected boolean useNames()

decorateComponentInstance

public Object decorateComponentInstance(PicoContainer container,
                                        Type into,
                                        Object instance)

Description copied from interface: Injector

A preexiting component instance can be injected into after instantiation

Specified by:

decorateComponentInstance in interface Injector

Parameters:

container - the container that can provide injectable dependencies

instance - the instance to

Returns:

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

@Deprecated
public Object getComponentInstance(PicoContainer container)
                            throws PicoCompositionException

Deprecated.

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.

Throws:

PicoCompositionException - if the component has dependencies which could not be resolved, or instantiation of the component lead to an ambigous situation within the container.

getComponentInstance

public Object getComponentInstance(PicoContainer container,
                                   Type into)
                            throws PicoCompositionException

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.

Throws:

PicoCompositionException - if the component has dependencies which could not be resolved, or instantiation of the component lead to an ambiguous situation within the container.

getProvideMethod

public static Method getProvideMethod(Class clazz)

verify

public void verify(PicoContainer container)
            throws PicoCompositionException

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.

Throws:

PicoCompositionException - if one or more dependencies cannot be resolved.

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

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.

Specified by:

getDescriptor in interface ComponentAdapter

Returns: