org.picocontainer.injectors
Class AbstractInjector<T>

java.lang.Object
  extended by org.picocontainer.adapters.AbstractAdapter<T>
      extended by org.picocontainer.injectors.AbstractInjector<T>
All Implemented Interfaces:
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
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  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, 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[] parameterTypes)
          Create default parameters for the given types.
 Object decorateComponentInstance(PicoContainer container, 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, Type into)
          Retrieve the component instance.
 String getDescriptor()
          Get a string key descriptor of the component adapter for use in toString()
protected  T newInstance(Constructor<T> constructor, 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(Object componentKey,
                           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
NullPointerException - if one of the parameters is null
Method Detail

useNames

public boolean useNames()

createDefaultParameters

protected Parameter[] createDefaultParameters(Type[] parameterTypes)
Create default parameters for the given types.

Parameters:
parameterTypes - 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.

decorateComponentInstance

public Object decorateComponentInstance(PicoContainer container,
                                        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 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(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)


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