Package org.rribbit.retrieval

Class DefaultListenerObjectRetriever

java.lang.Object

org.rribbit.retrieval.DefaultListenerObjectRetriever

All Implemented Interfaces:

ListenerObjectRetriever

Direct Known Subclasses:

CachedListenerObjectRetriever

public class DefaultListenerObjectRetriever
extends Object
implements ListenerObjectRetriever

This ListenerObjectRetriever provides common functionality that is required by typical implementations of ListenerObjectRetriever. This includes methods for checking whether a ListenerObject matches a certain request.

This class uses a List of ListenerObjectCreators for getting all ListenerObjects to search in. It does not keep a local copy of this collection, so implementations of ListenerObjectCreator are responsible of caching it.

This implementation is quite naieve, checking each ListenerObject in the Collection for a match everytime a request is made. Subclasses may replace this behaviour with more intelligent behaviour, such as caching of search results, or may implement ListenerObjectRetriever directly.

Author:

G.J. Schouten

Field Summary

Fields

Modifier and Type	Field	Description
protected List<ListenerObjectCreator>	listenerObjectCreators

Constructor Summary

Constructors

Constructor	Description
DefaultListenerObjectRetriever()	Whenever you use this constructor, be sure to set the ListenerObjectCreator with the setter provided by this class.
DefaultListenerObjectRetriever(ListenerObjectCreator... listenerObjectCreators)	This constructor is recommended, since it forces you to specify the ListenerObjectCreator.

Method Summary

Modifier and Type	Method	Description
void	addListenerObjectCreator(ListenerObjectCreator listenerObjectCreator)	Adds a ListenerObjectCreator to this DefaultListenerObjectRetriever.
List<ListenerObjectCreator>	getListenerObjectCreators()	Returns all ListenerObjectCreators that are used by this DefaultListenerObjectRetriever.
Collection<ListenerObject>	getListenerObjects()	Returns a Collection of all ListenerObjects that are known to this ListenerObjectRetriever.
Collection<ListenerObject>	getListenerObjects(Class<?> returnType)	Returns a Collection of ListenerObjects that satisfy the following requirements.
Collection<ListenerObject>	getListenerObjects(Class<?> returnType, String hint)	Returns a Collection of ListenerObjects that satisfy the following requirements.
Collection<ListenerObject>	getListenerObjects(String hint)	Returns a Collection of ListenerObjects that satisfy the following requirements.
protected Collection<ListenerObject>	getListenerObjectsFromAllCreators()
protected boolean	matchesHint(ListenerObject listenerObject, String hint)	Checks whether the ListenerObject matches the hint.
protected boolean	matchesReturnType(ListenerObject listenerObject, Class<?> returnType)	Checks whether the ListenerObject matches the returntype.
void	setListenerObjectCreator(ListenerObjectCreator listenerObjectCreator)	Removes all ListenerObjectCreators from this DefaultListenerObjectRetriever and adds only the given one.

Methods inherited from class java.lang.Object

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

Field Details

listenerObjectCreators

protected List<ListenerObjectCreator> listenerObjectCreators

Constructor Details

DefaultListenerObjectRetriever

public DefaultListenerObjectRetriever()

Whenever you use this constructor, be sure to set the ListenerObjectCreator with the setter provided by this class. If you don't, runtime NullPointerExceptions will occur.

DefaultListenerObjectRetriever

public DefaultListenerObjectRetriever(ListenerObjectCreator... listenerObjectCreators)

This constructor is recommended, since it forces you to specify the ListenerObjectCreator. Passing a null value for this will result in a runtime NullPointerException whenever the DefaultListenerObjectRetriever is used.

Parameters:

listenerObjectCreators -

Method Details

getListenerObjects

public Collection<ListenerObject> getListenerObjects()

Description copied from interface: ListenerObjectRetriever

Returns a Collection of all ListenerObjects that are known to this ListenerObjectRetriever.

Specified by:

getListenerObjects in interface ListenerObjectRetriever

Returns:

a Collection of all known ListenerObjects, or an empty Collection if there are none. This method never returns null.

getListenerObjects

public Collection<ListenerObject> getListenerObjects(Class<?> returnType)

Description copied from interface: ListenerObjectRetriever

Returns a Collection of ListenerObjects that satisfy the following requirements.

• The parameter 'returnType' is assignable from the returntype of the ListenerObject

Specified by:

getListenerObjects in interface ListenerObjectRetriever

Parameters:

returnType - the return type that has to be assignable from the returntype of each ListenerObject

Returns:

a Collection of ListenerObjects that satisfy the above requirements, or an empty Collection if there were no matches. This method never returns null.

getListenerObjects

public Collection<ListenerObject> getListenerObjects(String hint)

Description copied from interface: ListenerObjectRetriever

Returns a Collection of ListenerObjects that satisfy the following requirements.

• The hints of the ListenerObject must contain the 'hint' parameter

Specified by:

getListenerObjects in interface ListenerObjectRetriever

Parameters:

hint - the hint that has to be contained by the hints of each ListenerObject

Returns:

a Collection of ListenerObjects that satisfy the above requirements, or an empty Collection if there were no matches. This method never returns null.

getListenerObjects

public Collection<ListenerObject> getListenerObjects(Class<?> returnType,
 String hint)

Description copied from interface: ListenerObjectRetriever

Returns a Collection of ListenerObjects that satisfy the following requirements.

• The parameter 'returnType' is assignable from the returntype of the ListenerObject
• The hints of the ListenerObject must contain the 'hint' parameter

Specified by:

getListenerObjects in interface ListenerObjectRetriever

Parameters:

returnType - the return type that has to be assignable from the returntype of each ListenerObject

hint - the hint that has to be contained by the hints of each ListenerObject

Returns:

a Collection of ListenerObjects that satisfy the above requirements, or an empty Collection if there were no matches. This method never returns null.

getListenerObjectsFromAllCreators

protected Collection<ListenerObject> getListenerObjectsFromAllCreators()

matchesHint

protected boolean matchesHint(ListenerObject listenerObject,
 String hint)

Checks whether the ListenerObject matches the hint.

Parameters:

listenerObject -

hint -

Returns:

whether the ListenerObject matches the hint.

matchesReturnType

protected boolean matchesReturnType(ListenerObject listenerObject,
 Class<?> returnType)

Checks whether the ListenerObject matches the returntype.

Parameters:

listenerObject -

returnType -

Returns:

whether the ListenerObject matches the returntype.

getListenerObjectCreators

public List<ListenerObjectCreator> getListenerObjectCreators()

Returns all ListenerObjectCreators that are used by this DefaultListenerObjectRetriever.

Returns:

All ListenerObjectCreators that are used by this DefaultListenerObjectRetriever

addListenerObjectCreator

public void addListenerObjectCreator(ListenerObjectCreator listenerObjectCreator)

Adds a ListenerObjectCreator to this DefaultListenerObjectRetriever.

Parameters:

listenerObjectCreator - The ListenerObjectCreator that needs to be added to this DefaultListenerObjectRetriever

setListenerObjectCreator

public void setListenerObjectCreator(ListenerObjectCreator listenerObjectCreator)

Removes all ListenerObjectCreators from this DefaultListenerObjectRetriever and adds only the given one. After invoking this method, only the given ListenerObjectCreator will be used by this DefaultListenerObjectRetriever.

Parameters:

listenerObjectCreator - The ListenerObjectCreator that must be the sole ListenerObjectCreator used by this DefaultListenerObjectRetriever