rocks.xmpp.core.stream

Class FeatureNegotiator

java.lang.Object

rocks.xmpp.core.stream.FeatureNegotiator

Direct Known Subclasses:

AuthenticationManager, CompressionManager, SecurityManager

public abstract class FeatureNegotiator
extends Object

A base class to negotiate features.

Classes which extend from this class are responsible to negotiate a single feature.

Feature negotiators are registered with the FeaturesManager.addFeatureNegotiator(FeatureNegotiator) method.

Author:

Christian Schudt

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	FeatureNegotiator.Status Represents the status of the feature negotiation.

Constructor Summary

Constructors

Constructor and Description
FeatureNegotiator(Class<? extends StreamFeature> featureClass) Constructs a feature negotiator.

Method Summary

Modifier and Type	Method and Description
void	addFeatureListener(FeatureListener featureListener) Adds a feature listener, which will get notified about feature negotiation status changes.
abstract boolean	canProcess(Object element) Checks, whether the element can be processed by the feature negotiator.
Class<? extends StreamFeature>	getFeatureClass() Gets the feature class, this negotiator is responsible for.
boolean	needsRestart() Checks, if the feature needs a stream restart after it has been successfully negotiated.
protected void	notifyFeatureNegotiated(FeatureNegotiator.Status status, Object element) Notifies the listener, if a feature negotiation has completed.
abstract FeatureNegotiator.Status	processNegotiation(Object element) Processes a feature protocol element or the feature element itself.
void	removeFeatureListener(FeatureListener featureListener) Removes a previously added feature listener.

Methods inherited from class java.lang.Object

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

Constructor Detail

FeatureNegotiator

public FeatureNegotiator(Class<? extends StreamFeature> featureClass)

Constructs a feature negotiator.

Parameters:

featureClass - The feature class, which represents the feature, which will be negotiated.

Method Detail

addFeatureListener

public final void addFeatureListener(FeatureListener featureListener)

Adds a feature listener, which will get notified about feature negotiation status changes.

Parameters:

featureListener - The feature listener.

See Also:

removeFeatureListener(FeatureListener)

removeFeatureListener

public final void removeFeatureListener(FeatureListener featureListener)

Removes a previously added feature listener.

Parameters:

featureListener - The feature listener.

See Also:

addFeatureListener(FeatureListener)

notifyFeatureNegotiated

protected void notifyFeatureNegotiated(FeatureNegotiator.Status status,
                                       Object element)
                                throws Exception

Notifies the listener, if a feature negotiation has completed.

Parameters:

status - The status of the feature negotiation process.

element - The element, which triggered the feature status change.

Throws:

Exception - If an exception occurred during feature negotiation.

processNegotiation

public abstract FeatureNegotiator.Status processNegotiation(Object element)
                                                     throws Exception

Processes a feature protocol element or the feature element itself.

Parameters:

element - The XML element, which belongs to the feature negotiation, e.g. <challenge/> for SASL negotiation or the feature element itself, e.g. <mechanisms/>.

Returns:

The status of the feature negotiation.

Throws:

Exception - Any exception which might be thrown during a feature negotiation. Note that any exception thrown during the feature negotiation process is thrown by the XmppSession.connect() method and therefore will abort the connection process.

needsRestart

public boolean needsRestart()

Checks, if the feature needs a stream restart after it has been successfully negotiated. Override this method (returning true), if the feature requires a stream restart after negotiation.

By default this method returns false.

Returns:

True, if the stream requires a restart after feature negotiation.

canProcess

public abstract boolean canProcess(Object element)

Checks, whether the element can be processed by the feature negotiator.

Parameters:

element - The feature protocol element, e.g. <challenge/>. The element is never the feature element itself, e.g. <mechanisms/>, which is advertised in the <stream:features/> element.

Returns:

True, if the element can be processed by the feature negotiator.

getFeatureClass

public final Class<? extends StreamFeature> getFeatureClass()

Gets the feature class, this negotiator is responsible for.

Returns:

The feature class.