edu.UCL.satin.arch.components
Class Component

java.lang.Object
  edu.UCL.satin.arch.components.Component

All Implemented Interfaces:

ComponentFacet, Facet

Direct Known Subclasses:

AdvertisingServer, CentralAdvertising, Debug, Discovery, Reflective, Registrar, RemoteComponent, SimpleLocalHost

public abstract class Component

extends java.lang.Object

implements ComponentFacet

The SATIN component generalisation

Author:

Stefanos Zachariadis

Field Summary

protected boolean	immutable
protected java.util.Hashtable	properties

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

DISABLED, ENABLED

Constructor Summary

Component(java.lang.Object id)
Creates a new changeable component

Component(java.lang.Object id, boolean immutable, java.util.Hashtable properties)
Creates a new component with the given identifier.

Method Summary

boolean	addAttribute(GenericAttribute attr) Adds a new attribute to this component if it is not immutable
boolean	construct() The component constructor.
void	destroy() Destroys the component.
GenericAttribute	getAttribute(java.lang.Object key) Returns the attribute matching the given key.
java.util.Hashtable	getProperties() Returns a hashtable of all component attributes
boolean	hasAttribute(java.lang.Object id) Checks whether this component has the given attribute
boolean	isEnabled() Returns whether this component is enabled/active or not.
boolean	match(java.util.Hashtable properties) Checks whether this component satisfies the attributes given
void	setEnabled(boolean enabled) Activates or deactivates this component (if applicable).
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

properties

protected java.util.Hashtable properties

immutable

protected final boolean immutable

Constructor Detail

Component

public Component(java.lang.Object id)

Creates a new changeable component

Parameters:

id - the identifier of the component

Component

public Component(java.lang.Object id,
                 boolean immutable,
                 java.util.Hashtable properties)

Creates a new component with the given identifier.

Parameters:

id - the identifier of the component

immutable - whether or not the component is immutable. An immutable component cannot be reflective and cannot have any new attributes.

properties - the properties of this component

Method Detail

getAttribute

public GenericAttribute getAttribute(java.lang.Object key)

Returns the attribute matching the given key.

Specified by:

getAttribute in interface ComponentFacet

Parameters:

key - The key of the attribute

Returns:

The attribute matching this key, or null otherwise

hasAttribute

public boolean hasAttribute(java.lang.Object id)

Checks whether this component has the given attribute

Specified by:

hasAttribute in interface ComponentFacet

Parameters:

id - The key of the attribute to check

Returns:

true if the attribute exists, or false otherwise

getProperties

public java.util.Hashtable getProperties()

Returns a hashtable of all component attributes

Specified by:

getProperties in interface ComponentFacet

Returns:

all this component's attributes.

addAttribute

public boolean addAttribute(GenericAttribute attr)

Adds a new attribute to this component if it is not immutable

Specified by:

addAttribute in interface ComponentFacet

Parameters:

attr - The attribute to add

Returns:

true if the operation succeded or false if an attribute with the same key exists or the component is immutable.

toString

public java.lang.String toString()

isEnabled

public boolean isEnabled()

Returns whether this component is enabled/active or not. Note that unless overloaded, the component is assumed to always be enabled

Specified by:

isEnabled in interface ComponentFacet

Returns:

setEnabled

public void setEnabled(boolean enabled)

Activates or deactivates this component (if applicable). Note that unless overloaded, the component is assumed to always be enabled.

Specified by:

setEnabled in interface ComponentFacet

Parameters:

enabled -

match

public boolean match(java.util.Hashtable properties)

Checks whether this component satisfies the attributes given

Returns:

True if the component matches or false otherwise.

construct

public boolean construct()

Description copied from interface: ComponentFacet

The component constructor. This is where the component should obtain any references to other components/resources it needs.

Specified by:

construct in interface ComponentFacet

Returns:

true of the constrution was succesful, or false otherwise.

destroy

public void destroy()

Description copied from interface: ComponentFacet

Destroys the component. Done before removal. This is supposed to free up any resources etc that this component uses.

Specified by:

destroy in interface ComponentFacet