net.jini.core.lookup

Class ServiceEvent

java.lang.Object

java.util.EventObject

net.jini.core.event.RemoteEvent

net.jini.core.lookup.ServiceEvent

All Implemented Interfaces:

Serializable

public abstract class ServiceEvent
extends RemoteEvent

This class is used for remote events sent by the lookup service. It extends RemoteEvent with methods to obtain the service ID of the matched item, the transition that triggered the event, and the new state of the item.

Sequence numbers for a given event ID are strictly increasing. If there is no gap between two sequence numbers, no events have been missed; if there is a gap, events might (but might not) have been missed. For example, a gap might occur if the lookup service crashes, even if no events are lost due to the crash.

Since:

1.0

Author:

Sun Microsystems, Inc.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected ServiceID	serviceID ServiceID of the item that triggered the event.
protected int	transition One of ServiceRegistrar.TRANSITION_*MATCH_*MATCH.

Constructor Summary

Constructors

Constructor and Description
ServiceEvent(AtomicSerial.GetArg arg)
ServiceEvent(Object source, long eventID, long seqNo, MarshalledObject handback, ServiceID serviceID, int transition) Simple constructor.

Method Summary

Modifier and Type	Method and Description
Object	getBootstrapProxy() Returns a bootstrap proxy from which the new state of the item can be retrieved.
ServiceID	getServiceID() Returns the serviceID of the item that triggered the event.
abstract ServiceItem	getServiceItem() Returns the new state of the item, or null if the item was deleted from the lookup service.
int	getTransition() Returns the singleton transition that triggered the event.
String	toString() Returns a String representation of this ServiceEvent.

Methods inherited from class net.jini.core.event.RemoteEvent

getID, getRegistrationObject, getRegistrationObject2, getSequenceNumber, getSource

Methods inherited from class java.lang.Object

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

Field Detail

serviceID

protected final ServiceID serviceID

ServiceID of the item that triggered the event.

transition

protected final int transition

One of ServiceRegistrar.TRANSITION_*MATCH_*MATCH.

Constructor Detail

ServiceEvent

public ServiceEvent(AtomicSerial.GetArg arg)
             throws IOException

Throws:

IOException

ServiceEvent

public ServiceEvent(Object source,
                    long eventID,
                    long seqNo,
                    MarshalledObject handback,
                    ServiceID serviceID,
                    int transition)

Simple constructor.

Parameters:

source - the source of this ServiceEvent

eventID - the registration eventID

seqNo - the sequence number of this event

handback - the client handback

serviceID - the serviceID of the item that triggered the event

transition - the transition that triggered the event

Method Detail

getServiceID

public ServiceID getServiceID()

Returns the serviceID of the item that triggered the event.

Returns:

a ServiceID object representing the service ID value

getTransition

public int getTransition()

Returns the singleton transition that triggered the event.

Returns:

an int representing the transition value

toString

public String toString()

Returns a String representation of this ServiceEvent.

Overrides:

toString in class EventObject

Returns:

a String representation of this object

getServiceItem

public abstract ServiceItem getServiceItem()

Returns the new state of the item, or null if the item was deleted from the lookup service. It is preferable to delay unmarshalling the service proxy until this method is called.

Returns:

a ServiceItem object representing the service item value

getBootstrapProxy

public Object getBootstrapProxy()

Returns a bootstrap proxy from which the new state of the item can be retrieved. The returned bootstrap proxy should be prepared prior to use.

Returns:

a bootstrap proxy.