org.picocontainer

Interface Parameter

public interface Parameter

This class provides control over the arguments that will be passed to a constructor. It can be used for finer control over what arguments are passed to a particular constructor.

Since: 1.0

See Also: (Object,Class,Parameter[]) a method on the MutablePicoContainer interface which allows passing in of an array of Parameters. org.picocontainer.defaults.ComponentParameter an implementation of this interface that allows you to specify the key used for resolving the parameter. org.picocontainer.defaults.ConstantParameter an implementation of this interface that allows you to specify a constant that will be used for resolving the parameter.

Method Summary
voidaccept(PicoVisitor visitor)
Accepts a visitor for this Parameter.
booleanisResolvable(PicoContainer container, ComponentAdapter adapter, Class expectedType)
Check if the Parameter can statisfy the expected type using the container.
ObjectresolveInstance(PicoContainer container, ComponentAdapter adapter, Class expectedType)
Retrieve the object from the Parameter that statisfies the expected type.
voidverify(PicoContainer container, ComponentAdapter adapter, Class expectedType)
Verify that the Parameter can statisfied the expected type using the container

Method Detail

accept

public void accept(PicoVisitor visitor)
Accepts a visitor for this Parameter. The method is normally called by visiting a ComponentAdapter, that cascades the visitor also down to all its Parameters.

Parameters: visitor the visitor.

Since: 1.1

isResolvable

public boolean isResolvable(PicoContainer container, ComponentAdapter adapter, Class expectedType)
Check if the Parameter can statisfy the expected type using the container.

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 component parameter can be resolved.

Since: 1.1

resolveInstance

public Object resolveInstance(PicoContainer container, ComponentAdapter adapter, Class expectedType)
Retrieve the object from the Parameter that statisfies the expected type.

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.

Throws: PicoInitializationException if a referenced component could not be instantiated.

Since: 1.1

verify

public void verify(PicoContainer container, ComponentAdapter adapter, Class expectedType)
Verify that the Parameter can statisfied the expected type using the container

Parameters: container the container from which dependencies are resolved. adapter the ComponentAdapter that is asking for the verification expectedType the required type

Throws: PicoIntrospectionException if parameter and its dependencies cannot be resolved

Since: 1.1