org.picocontainer.injectors
Class MethodInjector<T>

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

All Implemented Interfaces:

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

Direct Known Subclasses:

MethodInjector.ByReflectionMethod

public class MethodInjector<T>
extends SingleMemberInjector<T>

Injection will happen through a single method for the component. Most likely it is a method called 'inject', though that can be overridden.

Author:

Paul Hammant, Aslak Hellesøy, Jon Tirsén, Zohar Melamed, Jörg Schaible, Mauro Talevi

See Also:

Serialized Form

Nested Class Summary

static class

MethodInjector.ByReflectionMethod

Nested classes/interfaces inherited from class org.picocontainer.injectors.SingleMemberInjector

SingleMemberInjector.ParameterCannotBeNullException

Nested classes/interfaces inherited from class org.picocontainer.injectors.AbstractInjector

AbstractInjector.AmbiguousComponentResolutionException, AbstractInjector.CyclicDependencyException, AbstractInjector.NotConcreteRegistrationException, AbstractInjector.UnsatisfiableDependenciesException

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

ComponentAdapter.NOTHING

Field Summary

Fields inherited from class org.picocontainer.injectors.AbstractInjector

parameters, verifyingGuard

Constructor Summary

MethodInjector(Object componentKey, Class componentImplementation, Parameter[] parameters, ComponentMonitor monitor, String methodName, boolean useNames)
Creates a MethodInjector

Method Summary

Object	decorateComponentInstance(PicoContainer container, Type into, T instance) A preexiting component instance can be injected into after instantiation
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 Method	getInjectorMethod()
protected Object[]	getMemberArguments(PicoContainer container, Method method)
protected boolean	isNullParamAllowed(AccessibleObject member, int i) Checks to see if a null parameter is allowed in the given constructor/field/method.
void	verify(PicoContainer container) Verify that all dependencies for this adapter can be satisfied.

Methods inherited from class org.picocontainer.injectors.SingleMemberInjector

boxParameters, getBindings, getMemberArguments, getParameter, getParanamer, nullCheck

Methods inherited from class org.picocontainer.injectors.AbstractInjector

accept, box, caughtIllegalAccessException, caughtIllegalAccessException, caughtInstantiationException, caughtInvocationTargetException, createDefaultParameters, getComponentInstance, newInstance, useNames

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

Constructor Detail

MethodInjector

public MethodInjector(Object componentKey,
                      Class componentImplementation,
                      Parameter[] parameters,
                      ComponentMonitor monitor,
                      String methodName,
                      boolean useNames)
               throws AbstractInjector.NotConcreteRegistrationException

Creates a MethodInjector

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 addAdapter

methodName - the method name

useNames - use argument names when looking up dependencies

Throws:

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

NullPointerException - if one of the parameters is null

Method Detail

getInjectorMethod

protected Method getInjectorMethod()

getComponentInstance

public 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>

Specified by:

getComponentInstance in class AbstractInjector<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.

getMemberArguments

protected Object[] getMemberArguments(PicoContainer container,
                                      Method method)

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>

Overrides:

decorateComponentInstance in class AbstractInjector<T>

Parameters:

container - the container that can provide injectable dependencies

instance - the instance to

Returns:

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>

Overrides:

verify in class AbstractInjector<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.

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>

Overrides:

getDescriptor in class AbstractInjector<T>

Returns:

the descriptor

isNullParamAllowed

protected boolean isNullParamAllowed(AccessibleObject member,
                                     int i)

Description copied from class: SingleMemberInjector

Checks to see if a null parameter is allowed in the given constructor/field/method. The default version allows null if the target object is not a primitive type.

Overrides:

isNullParamAllowed in class SingleMemberInjector<T>

Parameters:

member - constructor method or field

i - parameter #.

Returns:

true if the null parameter might be allowed.