net.sf.taverna.raven.spi
Class SpiRegistry

java.lang.Object
  net.sf.taverna.raven.spi.SpiRegistry

All Implemented Interfaces:

java.lang.Iterable<java.lang.Class>, ArtifactFilterListener

public class SpiRegistry
extends java.lang.Object
implements java.lang.Iterable<java.lang.Class>, ArtifactFilterListener

A typed registry of implementations of a particular Service Provider Interface (SPI). Discovery of these implementations is done using a similar mechanism to that employed by the Apache project commons-discovery that is to say a search for resources within known jar archives for META-INF/services/

Author:

Tom Oinn

Constructor Summary

SpiRegistry(Repository r, java.lang.String classname, java.lang.ClassLoader parentLoader)
Create a new SpiRegistry based on a particular repository and searching for the specified SPI classname.

Method Summary

void	addFilter(ArtifactFilter af) Add a new ArtifactFilter
void	addNewArtifact(Artifact a)
void	addRegistryListener(RegistryListener l) Add a new registry listener to be notified of any updates to this SpiRegistry
void	clearFilters() Clear all ArtifactFilter objects
void	filterChanged(ArtifactFilter filter)
void	finalize()
java.util.List<java.lang.Class>	getClasses() Get the Class objects for all implementations of this SPI currently known
java.lang.String	getClassName() The class name for the registry to search over
java.util.Iterator<java.lang.Class>	iterator()
void	removeRegistryListener(RegistryListener l) Remove a listener from this SpiRegistry
void	setFilters(java.util.List<ArtifactFilter> newFilters) Set the filter list
void	updateRegistry() Apply all filters to the set of new artifacts in turn, then for each Artifact which passes all the filters see if it contains a service entry for the SPI we're meant to be looking after.

Methods inherited from class java.lang.Object

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

Constructor Detail

SpiRegistry

public SpiRegistry(Repository r,
                   java.lang.String classname,
                   java.lang.ClassLoader parentLoader)

Create a new SpiRegistry based on a particular repository and searching for the specified SPI classname. Note that no scan for implementations is done at this point to allow interested parties to register SpiListener instances first.

Parameters:

r - the Repository which will be used to locate implementations of the SPI

classname - of the SPI to search for

parentLoader - a ClassLoader to use as the parent for any entries loaded here, or null for no parent (most likely behaviour is to leave as null)

Method Detail

addFilter

public void addFilter(ArtifactFilter af)

Add a new ArtifactFilter

addNewArtifact

public void addNewArtifact(Artifact a)

addRegistryListener

public void addRegistryListener(RegistryListener l)

Add a new registry listener to be notified of any updates to this SpiRegistry

Parameters:

l -

clearFilters

public void clearFilters()

Clear all ArtifactFilter objects

filterChanged

public void filterChanged(ArtifactFilter filter)

Specified by:

filterChanged in interface ArtifactFilterListener

finalize

public void finalize()

Overrides:

finalize in class java.lang.Object

getClasses

public java.util.List<java.lang.Class> getClasses()

Get the Class objects for all implementations of this SPI currently known

getClassName

public java.lang.String getClassName()

The class name for the registry to search over

iterator

public java.util.Iterator<java.lang.Class> iterator()

Specified by:

iterator in interface java.lang.Iterable<java.lang.Class>

removeRegistryListener

public void removeRegistryListener(RegistryListener l)

Remove a listener from this SpiRegistry

Parameters:

l -

setFilters

public void setFilters(java.util.List<ArtifactFilter> newFilters)

Set the filter list

updateRegistry

public void updateRegistry()

Apply all filters to the set of new artifacts in turn, then for each Artifact which passes all the filters see if it contains a service entry for the SPI we're meant to be looking after. If it does then parse the entry and extract the list of implementation classnames. Class objects corresponding to these are then added to the set of current known implementations.