org.glassfish.hk2.api
Interface Context<T>

Type Parameters:

T - This must be the type for which this is a context. For example, if your scope is SecureScope, then your context must implement Context<SecureScope>

All Known Implementing Classes:

PerThreadContext

@Contract
public interface Context<T>

An implementation of this must be put into the system in order to create contextual instances of services. If there is more than one active implementation available for the same scope on the same thread a runtime exception will be thrown when the scope is accessed.

An implementation of Context must be in the Singleton scope

Author:

jwells

Method Summary

boolean	containsKey(ActiveDescriptor<?> descriptor) Determines if this context has a value for the given key
void	destroyOne(ActiveDescriptor<?> descriptor) This method is called when ServiceHandle.destroy() method is called.
<U> U	findOrCreate(ActiveDescriptor<U> activeDescriptor, ServiceHandle<?> root) Creates a contextual instance of this ActiveDescriptor by calling its create method if there is no other matching contextual instance.
Class<? extends Annotation>	getScope() The scope for which this is the context
boolean	isActive() True if this context is active, false otherwise
void	shutdown() Shut down this context.
boolean	supportsNullCreation() Returns true if the findOrCreate method can return null

Method Detail

getScope

Class<? extends Annotation> getScope()

The scope for which this is the context

Returns:

may not return null, must return the scope for which this is a context

findOrCreate

<U> U findOrCreate(ActiveDescriptor<U> activeDescriptor,
                   ServiceHandle<?> root)

Creates a contextual instance of this ActiveDescriptor by calling its create method if there is no other matching contextual instance. If there is already a contextual instance it is returned. If parent is null then this must work like the find call

Parameters:

activeDescriptor - The descriptor to use when creating instances

root - The extended provider for the outermost parent being created

Returns:

A context instance. This value may NOT be null

containsKey

boolean containsKey(ActiveDescriptor<?> descriptor)

Determines if this context has a value for the given key

Parameters:

descriptor - The descriptor to look for in this context

Returns:

true if this context has a value associated with this descriptor

destroyOne

void destroyOne(ActiveDescriptor<?> descriptor)

This method is called when ServiceHandle.destroy() method is called. It is up to the context implementation whether or not to honor this destruction request based on the lifecycle requirements of the context

Parameters:

descriptor - A non-null descriptor upon which ServiceHandle.destroy() has been called

supportsNullCreation

boolean supportsNullCreation()

Returns true if the findOrCreate method can return null

Returns:

true if null is a legal value from the findOrCreate method

isActive

boolean isActive()

True if this context is active, false otherwise

Returns:

true if this context is active, false otherwise

shutdown

void shutdown()

Shut down this context.