com.sun.hk2.component
Class AbstractWombImpl<T>

java.lang.Object
  com.sun.hk2.component.AbstractInhabitantImpl<T>
      com.sun.hk2.component.AbstractWombImpl<T>

All Implemented Interfaces:

Holder<T>, Inhabitant<T>, Womb<T>

Direct Known Subclasses:

ConstructorWomb, FactoryWomb

public abstract class AbstractWombImpl<T>
extends AbstractInhabitantImpl<T>
implements Womb<T>

Author:

Kohsuke Kawaguchi

Nested Class Summary

Nested classes/interfaces inherited from interface com.sun.hk2.component.Holder

Holder.Impl<T>

Field Summary

protected java.lang.Class<T>

type

Constructor Summary

AbstractWombImpl(java.lang.Class<T> type, MultiMap<java.lang.String,java.lang.String> metadata)

Method Summary

T	get(Inhabitant onBehalfOf) Returns the instance of this inhabitant.
void	initialize(T t, Inhabitant onBehalfOf) Performs initialization of object, such as dependency injection.
protected void	inject(Habitat habitat, T t, Inhabitant onBehalfOf) Performs resource injection on the given instance from the given habitat.
MultiMap<java.lang.String,java.lang.String>	metadata() Gets the metadata associated with this inhabitant.
void	release() Called to orderly shutdown Habitat.
java.lang.Class<T>	type() Type of the inhabitant.
java.lang.String	typeName() The short-cut for type().getName() but this allows us to defer loading the actual types.

Methods inherited from class com.sun.hk2.component.AbstractInhabitantImpl

companions, get, getSerializedMetadata, getSerializedMetadata, lead, setCompanions

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.jvnet.hk2.component.Womb

create, get

Methods inherited from interface org.jvnet.hk2.component.Inhabitant

companions, getSerializedMetadata, getSerializedMetadata, lead, setCompanions

Field Detail

type

protected final java.lang.Class<T> type

Constructor Detail

AbstractWombImpl

public AbstractWombImpl(java.lang.Class<T> type,
                        MultiMap<java.lang.String,java.lang.String> metadata)

Method Detail

typeName

public final java.lang.String typeName()

Description copied from interface: Inhabitant

The short-cut for type().getName() but this allows us to defer loading the actual types.

Specified by:

typeName in interface Inhabitant<T>

type

public final java.lang.Class<T> type()

Description copied from interface: Inhabitant

Type of the inhabitant.

The only binding contract that needs to be honored is that the Inhabitant.get() method returns an instance assignable to this type. That is, get().getClass()==type() doesn't necessarily have to hold, but type().isInstance(get()) must.

This is particularly true when Factory is involved, as in such case HK2 has no way of knowing the actual type. That said, this method is not designed for the semantics of contract/implementation split --- implementations of a contract should return the concrete type from this method, and use habitat index to support look-up by contract.

Specified by:

type in interface Inhabitant<T>

Returns:

Always non-null, same value.

get

public final T get(Inhabitant onBehalfOf)
            throws ComponentException

Description copied from interface: Inhabitant

Returns the instance of this inhabitant.

THIS METHOD SHOULD BE ONLY USED BY HK2 IMPLEMENTATION.

Inhabitants are often used with the decorator pattern (see AbstractWombInhabitantImpl for example), yet during the object initializtion inside the Inhabitant.get() method, we often need the reference to the outer-most Inhabitant registered to the Habitat (for example so that we can request the injection of {link Inhabita} that represents itself, or to inject companions.)

So this overloaded version of the get method takes the outer-most Inhabitant. This method is only invoked from within HK2 where the decorator pattern is used.

Specified by:

get in interface Inhabitant<T>

Throws:

ComponentException

initialize

public void initialize(T t,
                       Inhabitant onBehalfOf)
                throws ComponentException

Description copied from interface: Womb

Performs initialization of object, such as dependency injection.

Specified by:

initialize in interface Womb<T>

Throws:

ComponentException

release

public void release()

Description copied from interface: Inhabitant

Called to orderly shutdown Habitat.

The expected behavior is for objects to get its PreDestroy callback invoked, and its reference released. For singleton objects, this method is expected to dispose that object.

For scoped objects, those are released when ScopeInstance.release() is invoked.

Specified by:

release in interface Inhabitant<T>

metadata

public MultiMap<java.lang.String,java.lang.String> metadata()

Description copied from interface: Inhabitant

Gets the metadata associated with this inhabitant.

This data is usually used by a sub-system of HK2, and not really meant to be used by applications. (At least for now.) The main benefit of metadata is that it's available right away as soon as the Habitat is properly initialized, even before component classes are loaded. In contrast, accessing annotations would require classes to be loaded and resolved.

Specified by:

metadata in interface Inhabitant<T>

Returns:

can be empty but never null. The values are read-only.

See Also:

Service.metadata()

inject

protected void inject(Habitat habitat,
                      T t,
                      Inhabitant onBehalfOf)

Performs resource injection on the given instance from the given habitat.

This method is an utility method for subclasses for performing injection.