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Class com.ibm.agletx.util.MessengerItinerary
java.lang.Object
|
+----com.ibm.aglet.event.MobilityAdapter
|
+----com.ibm.agletx.util.SeqItinerary
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+----com.ibm.agletx.util.MessengerItinerary
- public class MessengerItinerary
- extends SeqItinerary
An Itinerary class to broadcast a message to remote aglets. The message
is carried by a messenger aglet which visits the hosts
of the receiver aglets to send them the message, locally.
The following code segment shows a typical usage of this class.
public MessengerAglet extends Aglet {
MessengerItinerary itinerary;
Message message = new Message("test",null); // the message to broadcast
String receivers[] = .... // URIs of receiver aglets.
class MessengerItineraryx extends MessengerItinerary {
AgletProxy sender = null;
public MessengerItineraryx (Aglet aglet, Message msg, AgletProxy sender) {
super(aglet,msg);
this.sender=sender;
}
public void handleException (Throwable th) {
try {
sender.sendMessage(new Message("ack",th));
} catch (Exception ex) {
ex.printStackTrace();
}
th.printStackTrace();
}
}
public void onCreation(Object ini) {
AgletProxy sender = (AgletProxy)ini;
itinerary=new MessengerItineraryx(this,message,sender);
for (<every receiver in receivers[]>) {
itinerary.addAglet(<location of a receiver>,<ID of a receiver>);
}
itinerary.startTrip();
}
}
The above code defines the messenger aglet. Unlike one-way messaging, the
messenger aglet notifies its owner aglet (i.e. the creator aglet) in case
any of the receiver aglets can not be located.
In the code, the message to broadcast and the receiver aglets are saved
in the message and receivers instance variables,
respectivally. The MessangerItineraryx subclass overrides the
handleException() to notifies the creator aglet (via the message
Message("ack",ex)) of any exceptions encountered by the messenger
aglet. The invocation of itinerary.startTrip() causes the
messenger aglet to start its trip among the hosts of the receiver aglets.
-
MessengerItinerary(Aglet)
- Construct a MessengerItinerary object with a specified owner aglet
The message should be explicitly set by the setMessage()
-
MessengerItinerary(Aglet, Message)
- Construct a MessengerItinerary object with the specified owner aglet
and a message to broadcast.
-
MessengerItinerary(Aglet, String)
- Construct a MessengerItinerary object with the specified owner aglet
and a message to broadcast.
-
addAglet(String, AgletID)
- Add a new item [address, aglet id] to the itinerary.
-
getAgletAt(int)
- Return the URI of the aglet at the specified index.
-
getAglets()
- Return the enumeration of all the aglets to receive the broadcast
message
-
removeAglet(int)
- Remove an aglet from the plan at a specific index.
-
setMessage(Message)
- Set the message to be broadcast
-
setMessage(String)
- Set the message to be broadcast
MessengerItinerary
public MessengerItinerary(Aglet aglet,
Message msg)
- Construct a MessengerItinerary object with the specified owner aglet
and a message to broadcast.
- Parameters:
- aglet - the owner aglet
- msg - the message to be broadcasted
MessengerItinerary
public MessengerItinerary(Aglet aglet)
- Construct a MessengerItinerary object with a specified owner aglet
The message should be explicitly set by the setMessage()
- Parameters:
- aglet - the owner aglet
MessengerItinerary
public MessengerItinerary(Aglet aglet,
String msg)
- Construct a MessengerItinerary object with the specified owner aglet
and a message to broadcast.
- Parameters:
- aglet - the owner aglet
- msg - the message to br broadcasted
getAgletAt
public synchronized URL getAgletAt(int index) throws IOException
- Return the URI of the aglet at the specified index. The URI is
represented as + '#' + .
- Parameters:
- index - the specified index.
addAglet
public synchronized void addAglet(String address,
AgletID id)
- Add a new item [address, aglet id] to the itinerary.
- Parameters:
- address - the address of the aglet.
- id - the id of the aglet.
getAglets
public Enumeration getAglets()
- Return the enumeration of all the aglets to receive the broadcast
message
removeAglet
public synchronized void removeAglet(int index)
- Remove an aglet from the plan at a specific index.
- Parameters:
- index - the index to remove.
setMessage
public void setMessage(Message msg)
- Set the message to be broadcast
- Parameters:
- msg - the message
setMessage
public void setMessage(String msg)
- Set the message to be broadcast
- Parameters:
- msg - the message
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