org.picocontainer.defaults

Class BasicComponentParameter

java.lang.Object

org.picocontainer.defaults.BasicComponentParameter

All Implemented Interfaces:

java.io.Serializable, Parameter

Direct Known Subclasses:

ComponentParameter

public class BasicComponentParameter
extends java.lang.Object
implements Parameter, java.io.Serializable

A BasicComponentParameter should be used to pass in a particular component as argument to a different component's constructor. This is particularly useful in cases where several components of the same type have been registered, but with a different key. Passing a ComponentParameter as a parameter when registering a component will give PicoContainer a hint about what other component to use in the constructor. This Parameter will never resolve against a collecting type, that is not directly registered in the PicoContainer itself.

Version:

$Revision: 2817 $

Author:

Jon Tirsén, Aslak Hellesøy, Jörg Schaible, Thomas Heller

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static BasicComponentParameter	BASIC_DEFAULT BASIC_DEFAULT is an instance of BasicComponentParameter using the default constructor.
private java.lang.Object	componentKey

Constructor Summary

Constructors

Constructor and Description
BasicComponentParameter() Expect any paramter of the appropriate type.
BasicComponentParameter(java.lang.Object componentKey) Expect a parameter matching a component of a specific key.

Method Summary

Methods

Modifier and Type	Method and Description
void	accept(PicoVisitor visitor) Visit the current Parameter.
private ComponentAdapter	getTargetAdapter(PicoContainer container, java.lang.Class expectedType, ComponentAdapter excludeAdapter)
boolean	isResolvable(PicoContainer container, ComponentAdapter adapter, java.lang.Class expectedType) Check wether the given Parameter can be statisfied by the container.
private ComponentAdapter	resolveAdapter(PicoContainer container, ComponentAdapter adapter, java.lang.Class expectedType)
java.lang.Object	resolveInstance(PicoContainer container, ComponentAdapter adapter, java.lang.Class expectedType) Retrieve the object from the Parameter that statisfies the expected type.
void	verify(PicoContainer container, ComponentAdapter adapter, java.lang.Class expectedType) Verify that the Parameter can statisfied the expected type using the container

Methods inherited from class java.lang.Object

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

Field Detail

BASIC_DEFAULT

public static final BasicComponentParameter BASIC_DEFAULT

BASIC_DEFAULT is an instance of BasicComponentParameter using the default constructor.

componentKey

private java.lang.Object componentKey

Constructor Detail

BasicComponentParameter

public BasicComponentParameter(java.lang.Object componentKey)

Expect a parameter matching a component of a specific key.

Parameters:

componentKey - the key of the desired component

BasicComponentParameter

public BasicComponentParameter()

Expect any paramter of the appropriate type.

Method Detail

isResolvable

public boolean isResolvable(PicoContainer container,
                   ComponentAdapter adapter,
                   java.lang.Class expectedType)

Check wether the given Parameter can be statisfied by the container.

Specified by:

isResolvable in interface Parameter

Parameters:

container - the container from which dependencies are resolved.

adapter - the ComponentAdapter that is asking for the instance

expectedType - the required type

Returns:

true if the Parameter can be verified.

Throws:

PicoInitializationException

See Also:

Parameter.isResolvable(org.picocontainer.PicoContainer, org.picocontainer.ComponentAdapter, java.lang.Class)

resolveInstance

public java.lang.Object resolveInstance(PicoContainer container,
                               ComponentAdapter adapter,
                               java.lang.Class expectedType)

Description copied from interface: Parameter

Retrieve the object from the Parameter that statisfies the expected type.

Specified by:

resolveInstance in interface Parameter

Parameters:

container - the container from which dependencies are resolved.

adapter - the ComponentAdapter that is asking for the instance

expectedType - the type that the returned instance needs to match.

Returns:

the instance or null if no suitable instance can be found.

verify

public void verify(PicoContainer container,
          ComponentAdapter adapter,
          java.lang.Class expectedType)

Description copied from interface: Parameter

Verify that the Parameter can statisfied the expected type using the container

Specified by:

verify in interface Parameter

Parameters:

container - the container from which dependencies are resolved.

adapter - the ComponentAdapter that is asking for the verification

expectedType - the required type

accept

public void accept(PicoVisitor visitor)

Visit the current Parameter.

Specified by:

accept in interface Parameter

Parameters:

visitor - the visitor.

See Also:

Parameter.accept(org.picocontainer.PicoVisitor)

resolveAdapter

private ComponentAdapter resolveAdapter(PicoContainer container,
                              ComponentAdapter adapter,
                              java.lang.Class expectedType)

getTargetAdapter

private ComponentAdapter getTargetAdapter(PicoContainer container,
                                java.lang.Class expectedType,
                                ComponentAdapter excludeAdapter)