Package org.picocontainer.injectors

Class AbstractInjector<T>

java.lang.Object

org.picocontainer.adapters.AbstractAdapter<T>

org.picocontainer.injectors.AbstractInjector<T>

All Implemented Interfaces:

java.io.Serializable, ComponentAdapter<T>, ComponentMonitorStrategy, Injector<T>

Direct Known Subclasses:

CompositeInjector, IterativeInjector, SingleMemberInjector

public abstract class AbstractInjector<T>
extends AbstractAdapter<T>
implements Injector<T>

This ComponentAdapter will instantiate a new object for each call to ComponentAdapter.getComponentInstance(PicoContainer, Type). That means that when used with a PicoContainer, getComponent will return a new object each time.

Author:

Aslak Hellesøy, Paul Hammant, Jörg Schaible, Mauro Talevi

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	AbstractInjector.AmbiguousComponentResolutionException	Exception that is thrown as part of the introspection.
static class	AbstractInjector.CyclicDependencyException
static class	AbstractInjector.NotConcreteRegistrationException
static class	AbstractInjector.UnsatisfiableDependenciesException	Exception thrown when some of the component's dependencies are not satisfiable.

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

ComponentAdapter.NOTHING

Field Summary

Fields

Modifier and Type	Field	Description
protected Parameter[]	parameters	The parameters to use for initialization.
protected org.picocontainer.injectors.AbstractInjector.ThreadLocalCyclicDependencyGuard	verifyingGuard	The cycle guard for the verification.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractInjector(java.lang.Object componentKey, java.lang.Class<?> componentImplementation, Parameter[] parameters, ComponentMonitor monitor, boolean useNames)	Constructs a new ComponentAdapter for the given key and implementation.

Method Summary

Modifier and Type	Method	Description
void	accept(PicoVisitor visitor)	Accepts a visitor for this ComponentAdapter.
protected java.lang.reflect.Type	box(java.lang.reflect.Type parameterType)
protected T	caughtIllegalAccessException(ComponentMonitor componentMonitor, java.lang.reflect.Constructor<T> constructor, java.lang.IllegalAccessException e, PicoContainer container)	inform monitor about access exception.
protected java.lang.Object	caughtIllegalAccessException(ComponentMonitor componentMonitor, java.lang.reflect.Member member, java.lang.Object componentInstance, java.lang.IllegalAccessException e)
protected T	caughtInstantiationException(ComponentMonitor componentMonitor, java.lang.reflect.Constructor<T> constructor, java.lang.InstantiationException e, PicoContainer container)	inform monitor about component instantiation failure
protected T	caughtInvocationTargetException(ComponentMonitor componentMonitor, java.lang.reflect.Member member, java.lang.Object componentInstance, java.lang.reflect.InvocationTargetException e)	inform monitor about exception while instantiating component
protected Parameter[]	createDefaultParameters(int length)	Create default parameters for the given types.
java.lang.Object	decorateComponentInstance(PicoContainer container, java.lang.reflect.Type into, T instance)	A preexiting component instance can be injected into after instantiation
T	getComponentInstance(PicoContainer container)	Retrieve the component instance.
abstract T	getComponentInstance(PicoContainer container, java.lang.reflect.Type into)	Retrieve the component instance.
java.lang.String	getDescriptor()	Get a string key descriptor of the component adapter for use in toString()
protected T	newInstance(java.lang.reflect.Constructor<T> constructor, java.lang.Object[] parameters)	Instantiate an object with given parameters and respect the accessible flag.
boolean	useNames()
void	verify(PicoContainer container)	Verify that all dependencies for this adapter can be satisfied.

Methods inherited from class org.picocontainer.adapters.AbstractAdapter

changeMonitor, checkTypeCompatibility, currentMonitor, findAdapterOfType, getComponentImplementation, getComponentKey, getDelegate, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.picocontainer.ComponentAdapter

findAdapterOfType, getComponentImplementation, getComponentKey, getDelegate

Field Detail

verifyingGuard

protected transient org.picocontainer.injectors.AbstractInjector.ThreadLocalCyclicDependencyGuard verifyingGuard

The cycle guard for the verification.

parameters

protected transient Parameter[] parameters

The parameters to use for initialization.

Constructor Detail

AbstractInjector

protected AbstractInjector(java.lang.Object componentKey,
                           java.lang.Class<?> componentImplementation,
                           Parameter[] parameters,
                           ComponentMonitor monitor,
                           boolean useNames)

Constructs a new ComponentAdapter for the given key and implementation.

Parameters:

componentKey - the search key for this implementation

componentImplementation - the concrete implementation

parameters - the parameters to use for the initialization

monitor - the component monitor used by this ComponentAdapter

Throws:

AbstractInjector.NotConcreteRegistrationException - if the implementation is not a concrete class

java.lang.NullPointerException - if one of the parameters is null

Method Detail

useNames

public boolean useNames()

createDefaultParameters

protected Parameter[] createDefaultParameters(int length)

Create default parameters for the given types.

Parameters:

length - parameter list length

Returns:

the array with the default parameters.

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<T>

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.

getComponentInstance

public T getComponentInstance(PicoContainer container)
                       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<T>

Overrides:

getComponentInstance in class AbstractAdapter<T>

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 abstract T getComponentInstance(PicoContainer container,
                                       java.lang.reflect.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<T>

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.

decorateComponentInstance

public java.lang.Object decorateComponentInstance(PicoContainer container,
                                                  java.lang.reflect.Type into,
                                                  T instance)

Description copied from interface: Injector

A preexiting component instance can be injected into after instantiation

Specified by:

decorateComponentInstance in interface Injector<T>

Parameters:

container - the container that can provide injectable dependencies

instance - the instance to

Returns:

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<T>

Overrides:

accept in class AbstractAdapter<T>

Parameters:

visitor - the visitor.

getDescriptor

public java.lang.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<T>

Returns:

the descriptor

newInstance

protected T newInstance(java.lang.reflect.Constructor<T> constructor,
                        java.lang.Object[] parameters)
                 throws java.lang.InstantiationException,
                        java.lang.IllegalAccessException,
                        java.lang.reflect.InvocationTargetException

Instantiate an object with given parameters and respect the accessible flag.

Parameters:

constructor - the constructor to use

parameters - the parameters for the constructor

Returns:

the new object.

Throws:

java.lang.InstantiationException

java.lang.IllegalAccessException

java.lang.reflect.InvocationTargetException

caughtInstantiationException

protected T caughtInstantiationException(ComponentMonitor componentMonitor,
                                         java.lang.reflect.Constructor<T> constructor,
                                         java.lang.InstantiationException e,
                                         PicoContainer container)

inform monitor about component instantiation failure

Parameters:

componentMonitor -

constructor -

e -

container -

Returns:

caughtIllegalAccessException

protected T caughtIllegalAccessException(ComponentMonitor componentMonitor,
                                         java.lang.reflect.Constructor<T> constructor,
                                         java.lang.IllegalAccessException e,
                                         PicoContainer container)

inform monitor about access exception.

Parameters:

componentMonitor -

constructor -

e -

container -

Returns:

caughtInvocationTargetException

protected T caughtInvocationTargetException(ComponentMonitor componentMonitor,
                                            java.lang.reflect.Member member,
                                            java.lang.Object componentInstance,
                                            java.lang.reflect.InvocationTargetException e)

inform monitor about exception while instantiating component

Parameters:

componentMonitor -

member -

componentInstance -

e -

Returns:

caughtIllegalAccessException

protected java.lang.Object caughtIllegalAccessException(ComponentMonitor componentMonitor,
                                                        java.lang.reflect.Member member,
                                                        java.lang.Object componentInstance,
                                                        java.lang.IllegalAccessException e)

box

protected java.lang.reflect.Type box(java.lang.reflect.Type parameterType)