org.picocontainer

Interface Parameter

All Known Implementing Classes:

AbstractParameter, BasicComponentParameter, CollectionComponentParameter, ComponentParameter, ConstantParameter, DefaultConstructorParameter, NullParameter

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.

Author:

Jon Tirsén, Aslak Hellesøy, Thomas Heller

See Also:

a method on the {@link MutablePicoContainer} interface which allows passing in of an array of {@linkplain Parameter Parameters}., an implementation of this interface that allows you to specify the key used for resolving the parameter., an implementation of this interface that allows you to specify a constant that will be used for resolving the parameter.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	Parameter.DelegateResolver Delegate to another reolver
static class	Parameter.NotResolved The Parameter cannot (ever) be resolved
static interface	Parameter.Resolver Resolver is used transitarily during resolving of Parameters.
static class	Parameter.ValueResolver A fixed value wrapped as a Resolver

Field Summary

Fields

Modifier and Type	Field and Description
static Parameter[]	DEFAULT
static Parameter[]	ZERO Zero parameter is used when you wish a component to be instantiated with its default constructor.

Method Summary

Methods

Modifier and Type	Method and Description
void	accept(PicoVisitor visitor) Accepts a visitor for this Parameter.
boolean	isResolvable(PicoContainer container, ComponentAdapter<?> forAdapter, Type expectedType, NameBinding expectedNameBinding, boolean useNames, Annotation binding) Deprecated.
Parameter.Resolver	resolve(PicoContainer container, ComponentAdapter<?> forAdapter, ComponentAdapter<?> injecteeAdapter, Type expectedType, NameBinding expectedNameBinding, boolean useNames, Annotation binding) Check if the Parameter can satisfy the expected type using the container.
Object	resolveInstance(PicoContainer container, ComponentAdapter<?> forAdapter, Type expectedType, NameBinding expectedNameBinding, boolean useNames, Annotation binding) Deprecated.
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

Field Detail

ZERO

static final Parameter[] ZERO

Zero parameter is used when you wish a component to be instantiated with its default constructor. Ex:

                MutablePicoContainer mpc = new PicoBuilder().build();
                mpc.addComponent(Map.class, HashMap.class, Parameter.ZERO);
                mpc.addComponent(List.class, ArrayList.class, Parameter.ZERO);
        

By specifying the default constructor in this example code, you allow PicoContainer to recognize that HashMap(Collection) should not be used and avoid a CircularDependencyException.

DEFAULT

static final Parameter[] DEFAULT

Method Detail

resolve

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

Check if the Parameter can satisfy the expected type using the container.

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.

Since:

2.8.1

verify

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

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

useNames -

binding -

Throws:

PicoCompositionException - if parameter and its dependencies cannot be resolved

accept

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.

resolveInstance

@Deprecated
Object resolveInstance(PicoContainer container,
                                ComponentAdapter<?> forAdapter,
                                Type expectedType,
                                NameBinding expectedNameBinding,
                                boolean useNames,
                                Annotation binding)

Deprecated.

isResolvable

@Deprecated
boolean isResolvable(PicoContainer container,
                              ComponentAdapter<?> forAdapter,
                              Type expectedType,
                              NameBinding expectedNameBinding,
                              boolean useNames,
                              Annotation binding)

Deprecated.