org.picocontainer.injectors

Class ProviderAdapter

java.lang.Object

org.picocontainer.injectors.ProviderAdapter

All Implemented Interfaces:

ComponentAdapter, Injector, Provider, LifecycleStrategy

public class ProviderAdapter
extends Object
implements Injector, Provider, LifecycleStrategy

Providers are a type of Injector that can participate in Injection via a custom method. Implementers 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

Constructors

Modifier	Constructor and Description
protected	ProviderAdapter()
	ProviderAdapter(LifecycleStrategy lifecycleStrategy, Provider provider)
	ProviderAdapter(LifecycleStrategy lifecycleStrategy, Provider provider, boolean useNames)
	ProviderAdapter(Provider provider)
	ProviderAdapter(Provider provider, boolean useNames)

Method Summary

Methods

Modifier and Type	Method and Description
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
void	dispose(Object component) Invoke the "dispose" method on the component instance if this is disposable.
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 for use in toString()
static Method	getProvideMethod(Class clazz)
boolean	hasLifecycle(Class<?> type) Test if a component instance has a lifecycle.
boolean	isLazy(ComponentAdapter<?> adapter) Is a component eager (not lazy) in that it should start when start() or equivalent is called, or lazy (it will only start on first getComponent() ).
void	start(Object component) Invoke the "start" method on the component instance if this is startable.
void	stop(Object component) Invoke the "stop" method on the component instance if this is stoppable.
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(LifecycleStrategy lifecycleStrategy,
               Provider provider)

ProviderAdapter

public ProviderAdapter(Provider provider)

ProviderAdapter

public ProviderAdapter(Provider provider,
               boolean useNames)

ProviderAdapter

public ProviderAdapter(LifecycleStrategy lifecycleStrategy,
               Provider 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

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

start

public void start(Object component)

Description copied from interface: LifecycleStrategy

Invoke the "start" method on the component instance if this is startable. It is up to the implementation of the strategy what "start" and "startable" means.

Specified by:

start in interface LifecycleStrategy

Parameters:

component - the instance of the component to start

stop

public void stop(Object component)

Description copied from interface: LifecycleStrategy

Invoke the "stop" method on the component instance if this is stoppable. It is up to the implementation of the strategy what "stop" and "stoppable" means.

Specified by:

stop in interface LifecycleStrategy

Parameters:

component - the instance of the component to stop

dispose

public void dispose(Object component)

Description copied from interface: LifecycleStrategy

Invoke the "dispose" method on the component instance if this is disposable. It is up to the implementation of the strategy what "dispose" and "disposable" means.

Specified by:

dispose in interface LifecycleStrategy

Parameters:

component - the instance of the component to dispose

hasLifecycle

public boolean hasLifecycle(Class<?> type)

Description copied from interface: LifecycleStrategy

Test if a component instance has a lifecycle.

Specified by:

hasLifecycle in interface LifecycleStrategy

Parameters:

type - the component's type

Returns:

true if the component has a lifecycle

isLazy

public boolean isLazy(ComponentAdapter<?> adapter)

Description copied from interface: LifecycleStrategy

Is a component eager (not lazy) in that it should start when start() or equivalent is called, or lazy (it will only start on first getComponent() ). The default is the first of those two.

Specified by:

isLazy in interface LifecycleStrategy

Returns:

true if lazy, false if not lazy