edu.UCL.satin.impl.registrar
Class CoreRegistrar

java.lang.Object
  edu.UCL.satin.arch.components.Component
      edu.UCL.satin.arch.components.container.Registrar
          edu.UCL.satin.impl.registrar.CoreRegistrar

All Implemented Interfaces:

ComponentFacet, Facet, RegistrarFacet

public class CoreRegistrar

extends Registrar

Author:

Stefanos Zachariadis

Field Summary

private boolean	enabled
private java.util.Vector	listeners
private java.util.Hashtable	repo

Fields inherited from class edu.UCL.satin.arch.components.Component

immutable, properties

Fields inherited from interface edu.UCL.satin.arch.facets.ComponentFacet

DISABLED, ENABLED

Constructor Summary

CoreRegistrar(java.util.Hashtable repo, java.util.Vector listeners)
Creates a new registrar, using the given hashtable as the actual registry and the given vector as the collection of listeners.

Method Summary

private void	checkListeners(Component c)
boolean	isEnabled() Checks whether this component is enabled or not.
boolean	registerComponent(Component c) Adds a new component to the container.
java.lang.String	removeComponent(Component c) Removes a component from the container
void	setEnabled(boolean enabled) Enables or disables the component
private static boolean	subset(java.util.Hashtable a, java.util.Hashtable b) Returns true if a is a subset of b

Methods inherited from class edu.UCL.satin.arch.components.Component

addAttribute, construct, destroy, getAttribute, getProperties, hasAttribute, match, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface edu.UCL.satin.arch.facets.ComponentFacet

addAttribute, construct, destroy, getAttribute, getProperties, hasAttribute

Field Detail

repo

private java.util.Hashtable repo

listeners

private java.util.Vector listeners

enabled

private boolean enabled

Constructor Detail

CoreRegistrar

public CoreRegistrar(java.util.Hashtable repo,
                     java.util.Vector listeners)

Creates a new registrar, using the given hashtable as the actual registry and the given vector as the collection of listeners. IMPORTANT We assume that components have a GenericAttribute, with key ID and a String as a value to represent their identifier We assume that components have a GenericAttribute, with key VER and an Integer object as a value to represent their version. We will add (VER,1) if this is missing We assume that components have a GenericAttribute, with key DEP and a String of IDs, separated by "," as a value, to represent their dependencies. If they don't have a DEP attribute, then they are atomic

Parameters:

repo -

listeners -

Method Detail

registerComponent

public boolean registerComponent(Component c)

Description copied from class: Registrar

Adds a new component to the container.

Specified by:

registerComponent in interface RegistrarFacet

Specified by:

registerComponent in class Registrar

Parameters:

c - The component to add

Returns:

true if the operation was successful or false otherwise (component with the same id and version number exist/failure/etc.)

removeComponent

public java.lang.String removeComponent(Component c)

Description copied from class: Registrar

Removes a component from the container

Specified by:

removeComponent in interface RegistrarFacet

Specified by:

removeComponent in class Registrar

Parameters:

c - The component to remove

Returns:

null if the operation was successful or the ID of the component that depends on c

checkListeners

private void checkListeners(Component c)

subset

private static boolean subset(java.util.Hashtable a,
                              java.util.Hashtable b)

Returns true if a is a subset of b

Returns:

true if a is a subset of b, or false otherwise

setEnabled

public void setEnabled(boolean enabled)

Description copied from interface: ComponentFacet

Enables or disables the component

Specified by:

setEnabled in interface ComponentFacet

Overrides:

setEnabled in class Component

Parameters:

enabled -

isEnabled

public boolean isEnabled()

Description copied from interface: ComponentFacet

Checks whether this component is enabled or not.

Specified by:

isEnabled in interface ComponentFacet

Overrides:

isEnabled in class Component

Returns: