Package org.apache.tapestry5.commons.util

Class StrategyRegistry<A>

java.lang.Object

org.apache.tapestry5.commons.util.StrategyRegistry<A>

Type Parameters:

A - the type of the strategy adapter

public final class StrategyRegistry<A>
extends Object

A key component in implementing the "Gang of Four" Strategy pattern. A StrategyRegistry will match up a given input type with a registered strategy for that type.

Method Summary

Modifier and Type	Method	Description
void	clearCache()
A	get(Class type)	Searches for an adapter corresponding to the given input type.
Class<A>	getAdapterType()
A	getByInstance(Object value)	Gets an adapter for an object.
Collection<Class>	getTypes()	Returns the registered types for which adapters are available.
static <A> StrategyRegistry<A>	newInstance(Class<A> adapterType, Map<Class,A> registrations)	Creates a strategy registry for the given adapter type.
static <A> StrategyRegistry<A>	newInstance(Class<A> adapterType, Map<Class,A> registrations, boolean allowNonMatch)	Creates a strategy registry for the given adapter type.
String	toString()

Methods inherited from class java.lang.Object

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

Method Detail

newInstance

public static <A> StrategyRegistry<A> newInstance(Class<A> adapterType,
                                                  Map<Class,A> registrations)

Creates a strategy registry for the given adapter type. The registry will be configured to require matches.

Parameters:

adapterType - the type of adapter retrieved from the registry

registrations - map of registrations (the contents of the map are copied)

newInstance

public static <A> StrategyRegistry<A> newInstance(Class<A> adapterType,
                                                  Map<Class,A> registrations,
                                                  boolean allowNonMatch)

Creates a strategy registry for the given adapter type.

Parameters:

adapterType - the type of adapter retrieved from the registry

registrations - map of registrations (the contents of the map are copied)

allowNonMatch - if true, then the registry supports non-matches when retrieving an adapter

clearCache

public void clearCache()

getAdapterType

public Class<A> getAdapterType()

getByInstance

public A getByInstance(Object value)

Gets an adapter for an object. Searches based on the value's class, unless the value is null, in which case, a search on class void is used.

Parameters:

value - for which an adapter is needed

Returns:

the adapter for the value or null if not found (and allowNonMatch is true)

Throws:

IllegalArgumentException - if no matching adapter may be found and allowNonMatch is false

get

public A get(Class type)

Searches for an adapter corresponding to the given input type.

Parameters:

type - the type to search

Returns:

the adapter for the type or null if not found (and allowNonMatch is true)

Throws:

IllegalArgumentException - if no matching adapter may be found and allowNonMatch is false

getTypes

public Collection<Class> getTypes()

Returns the registered types for which adapters are available.

toString

public String toString()

Overrides:

toString in class Object