org.picocontainer.injectors
Class AbstractInjector<T>

java.lang.Object
  org.picocontainer.adapters.AbstractAdapter<T>
      org.picocontainer.injectors.AbstractInjector<T>

All Implemented Interfaces:

Serializable, ComponentAdapter<T>, ComponentMonitorStrategy, Injector<T>, LifecycleStrategy

Direct Known Subclasses:

CompositeInjector, IterativeInjector, SingleMemberInjector

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

This ComponentAdapter will instantiate a new object for each call to org.picocontainer.ComponentAdapter#getComponentInstance(PicoContainer, Class). 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

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

protected LifecycleStrategy	lifecycleStrategy The strategy used to control the lifecycle
protected Parameter[]	parameters The parameters to use for initialization.
protected org.picocontainer.injectors.AbstractInjector.ThreadLocalCyclicDependencyGuard	verifyingGuard The cycle guard for the verification.

Constructor Summary

protected

AbstractInjector(Object componentKey, Class<?> componentImplementation, Parameter[] parameters, ComponentMonitor monitor, LifecycleStrategy lifecycleStrategy, boolean useNames) Constructs a new ComponentAdapter for the given key and implementation.

Method Summary

void	accept(PicoVisitor visitor) Accepts a visitor for this ComponentAdapter.
protected Type	box(Type parameterType)
protected T	caughtIllegalAccessException(ComponentMonitor componentMonitor, Constructor<T> constructor, IllegalAccessException e, PicoContainer container) inform monitor about access exception.
protected Object	caughtIllegalAccessException(ComponentMonitor componentMonitor, Member member, Object componentInstance, IllegalAccessException e)
protected T	caughtInstantiationException(ComponentMonitor componentMonitor, Constructor<T> constructor, InstantiationException e, PicoContainer container) inform monitor about component instantiation failure
protected T	caughtInvocationTargetException(ComponentMonitor componentMonitor, Member member, Object componentInstance, InvocationTargetException e) inform monitor about exception while instantiating component
protected Parameter[]	createDefaultParameters(Type[] parameters) Create default parameters for the given types.
void	dispose(Object component) Invoke the "dispose" method on the component instance if this is disposable.
T	getComponentInstance(PicoContainer container) Retrieve the component instance.
abstract T	getComponentInstance(PicoContainer container, Type into) Retrieve the component instance.
String	getDescriptor() Get a string key descriptor of the component adapter.
boolean	hasLifecycle(Class<?> type) Test if a component instance has a lifecycle.
protected T	newInstance(Constructor<T> constructor, Object[] parameters) Instantiate an object with given parameters and respect the accessible flag.
void	start(Object component) Invoke the "start" method on the component instance if this is startable.
void	stop(Object component) Invoke the "stop" method on the component instance if this is stoppable.
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.Injector

decorateComponentInstance

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.

lifecycleStrategy

protected LifecycleStrategy lifecycleStrategy

The strategy used to control the lifecycle

Constructor Detail

AbstractInjector

protected AbstractInjector(Object componentKey,
                           Class<?> componentImplementation,
                           Parameter[] parameters,
                           ComponentMonitor monitor,
                           LifecycleStrategy lifecycleStrategy,
                           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

lifecycleStrategy - the lifecycle strategy used by this ComponentAdapter

Throws:

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

NullPointerException - if one of the parameters is null

Method Detail

useNames

public boolean useNames()

createDefaultParameters

protected Parameter[] createDefaultParameters(Type[] parameters)

Create default parameters for the given types.

Parameters:

parameters - the parameter types

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,
                                       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.

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.

start

public void start(Object component)

Description copied from interface: LifecycleStrategy

Invoke the "start" method on the component instance if this is startable. It is up to the implementation of the strategy what "start" and "startable" means.

Specified by:

start in interface LifecycleStrategy

Parameters:

component - the instance of the component to start

stop

public void stop(Object component)

Description copied from interface: LifecycleStrategy

Invoke the "stop" method on the component instance if this is stoppable. It is up to the implementation of the strategy what "stop" and "stoppable" means.

Specified by:

stop in interface LifecycleStrategy

Parameters:

component - the instance of the component to stop

dispose

public void dispose(Object component)

Description copied from interface: LifecycleStrategy

Invoke the "dispose" method on the component instance if this is disposable. It is up to the implementation of the strategy what "dispose" and "disposable" means.

Specified by:

dispose in interface LifecycleStrategy

Parameters:

component - the instance of the component to dispose

hasLifecycle

public boolean hasLifecycle(Class<?> type)

Description copied from interface: LifecycleStrategy

Test if a component instance has a lifecycle.

Specified by:

hasLifecycle in interface LifecycleStrategy

Parameters:

type - the component's type

Returns:

true if the component has a lifecycle

getDescriptor

public String getDescriptor()

Description copied from interface: ComponentAdapter

Get a string key descriptor of the component adapter.

Specified by:

getDescriptor in interface ComponentAdapter<T>

Returns:

newInstance

protected T newInstance(Constructor<T> constructor,
                        Object[] parameters)
                 throws InstantiationException,
                        IllegalAccessException,
                        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:

InstantiationException

IllegalAccessException

InvocationTargetException

caughtInstantiationException

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

inform monitor about component instantiation failure

Parameters:

componentMonitor -

constructor -

e -

container -

Returns:

caughtIllegalAccessException

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

inform monitor about access exception.

Parameters:

componentMonitor -

constructor -

e -

container -

Returns:

caughtInvocationTargetException

protected T caughtInvocationTargetException(ComponentMonitor componentMonitor,
                                            Member member,
                                            Object componentInstance,
                                            InvocationTargetException e)

inform monitor about exception while instantiating component

Parameters:

componentMonitor -

member -

componentInstance -

e -

Returns:

caughtIllegalAccessException

protected Object caughtIllegalAccessException(ComponentMonitor componentMonitor,
                                              Member member,
                                              Object componentInstance,
                                              IllegalAccessException e)

box

protected Type box(Type parameterType)