org.picocontainer.parameters
Class ComponentParameter

java.lang.Object
  org.picocontainer.parameters.AbstractParameter
      org.picocontainer.parameters.BasicComponentParameter
          org.picocontainer.parameters.ComponentParameter

All Implemented Interfaces:

Serializable, Parameter

public class ComponentParameter
extends BasicComponentParameter

A ComponentParameter 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. Collecting parameter types are supported for Array,Collectionand Map.

Author:

Jon Tirsén, Aslak Hellesøy, Jörg Schaible, Thomas Heller

See Also:

Serialized Form

Nested Class Summary

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

Parameter.DelegateResolver, Parameter.NotResolved, Parameter.Resolver, Parameter.ValueResolver

Field Summary

static ComponentParameter	ARRAY Use ARRAY as Parameterfor an Array that must have elements.
static ComponentParameter	ARRAY_ALLOW_EMPTY Use ARRAY_ALLOW_EMPTY as Parameterfor an Array that may have no elements.
static ComponentParameter	DEFAULT DEFAULT is an instance of ComponentParameter using the default constructor.

Fields inherited from class org.picocontainer.parameters.BasicComponentParameter

BASIC_DEFAULT

Fields inherited from interface org.picocontainer.Parameter

ZERO

Constructor Summary

ComponentParameter()
Expect any scalar parameter of the appropriate type or an Array.

ComponentParameter(boolean emptyCollection)
Expect any scalar parameter of the appropriate type or an Array.

ComponentParameter(Class componentValueType, boolean emptyCollection)
Expect any scalar parameter of the appropriate type or the collecting type Array,Collectionor Map.

ComponentParameter(Class componentKeyType, Class componentValueType, boolean emptyCollection)
Expect any scalar parameter of the appropriate type or the collecting type Array,Collectionor Map.

ComponentParameter(Object componentKey)
Expect a parameter matching a component of a specific key.

Method Summary

void	accept(PicoVisitor visitor) Accept the visitor for the current Parameter.
Parameter.Resolver	resolve(PicoContainer container, ComponentAdapter<?> forAdapter, ComponentAdapter<?> injecteeAdapter, Type expectedType, NameBinding expectedNameBinding, boolean useNames, Annotation binding) Check whether the given Parameter can be satisfied by the container.
void	verify(PicoContainer container, ComponentAdapter<?> adapter, Type expectedType, NameBinding expectedNameBinding, boolean useNames, Annotation binding) Verify that the Parameter can satisfy the expected type using the container

Methods inherited from class org.picocontainer.parameters.BasicComponentParameter

resolveAdapter

Methods inherited from class org.picocontainer.parameters.AbstractParameter

isResolvable, resolveInstance

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.picocontainer.Parameter

isResolvable, resolveInstance

Field Detail

DEFAULT

public static final ComponentParameter DEFAULT

DEFAULT is an instance of ComponentParameter using the default constructor.

ARRAY

public static final ComponentParameter ARRAY

Use ARRAY as Parameterfor an Array that must have elements.

ARRAY_ALLOW_EMPTY

public static final ComponentParameter ARRAY_ALLOW_EMPTY

Use ARRAY_ALLOW_EMPTY as Parameterfor an Array that may have no elements.

Constructor Detail

ComponentParameter

public ComponentParameter(Object componentKey)

Expect a parameter matching a component of a specific key.

Parameters:

componentKey - the key of the desired addComponent

ComponentParameter

public ComponentParameter()

Expect any scalar parameter of the appropriate type or an Array.

ComponentParameter

public ComponentParameter(boolean emptyCollection)

Expect any scalar parameter of the appropriate type or an Array. Resolve the parameter even if no compnoent is of the array's component type.

Parameters:

emptyCollection - true allows an Array to be empty

ComponentParameter

public ComponentParameter(Class componentValueType,
                          boolean emptyCollection)

Expect any scalar parameter of the appropriate type or the collecting type Array,Collectionor Map. The components in the collection will be of the specified type.

Parameters:

componentValueType - the component's type (ignored for an Array)

emptyCollection - true allows the collection to be empty

ComponentParameter

public ComponentParameter(Class componentKeyType,
                          Class componentValueType,
                          boolean emptyCollection)

Expect any scalar parameter of the appropriate type or the collecting type Array,Collectionor Map. The components in the collection will be of the specified type and their adapter's key must have a particular type.

Parameters:

componentKeyType - the component adapter's key type

componentValueType - the component's type (ignored for an Array)

emptyCollection - true allows the collection to be empty

Method Detail

resolve

public Parameter.Resolver resolve(PicoContainer container,
                                  ComponentAdapter<?> forAdapter,
                                  ComponentAdapter<?> injecteeAdapter,
                                  Type expectedType,
                                  NameBinding expectedNameBinding,
                                  boolean useNames,
                                  Annotation binding)

Description copied from class: BasicComponentParameter

Check whether the given Parameter can be satisfied by the container.

Specified by:

resolve in interface Parameter

Overrides:

resolve in class BasicComponentParameter

Parameters:

container - the container from which dependencies are resolved.

forAdapter - the ComponentAdapter that is asking for the instance

injecteeAdapter - the adapter to be injected into (null for N/A)

expectedType - the required type

expectedNameBinding - Expected parameter name

useNames - should use parameter names for disambiguation

binding - @return true if the component parameter can be resolved.

Returns:

true if the Parameter can be verified.

See Also:

Parameter#isResolvable(PicoContainer, ComponentAdapter, Class, NameBinding ,boolean, Annotation)

verify

public void verify(PicoContainer container,
                   ComponentAdapter<?> adapter,
                   Type expectedType,
                   NameBinding expectedNameBinding,
                   boolean useNames,
                   Annotation binding)

Description copied from interface: Parameter

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

Specified by:

verify in interface Parameter

Overrides:

verify in class BasicComponentParameter

Parameters:

container - the container from which dependencies are resolved.

adapter - the ComponentAdapter that is asking for the verification

expectedType - the required type

expectedNameBinding - Expected parameter name

accept

public void accept(PicoVisitor visitor)

Accept the visitor for the current Parameter. If internally a CollectionComponentParameteris used, it is visited also.

Specified by:

accept in interface Parameter

Overrides:

accept in class BasicComponentParameter

Parameters:

visitor - the visitor.

See Also:

BasicComponentParameter.accept(org.picocontainer.PicoVisitor)