Package org.jgroups

Class StreamingGetStateEvent

java.lang.Object

org.jgroups.StreamingGetStateEvent

public class StreamingGetStateEvent
extends java.lang.Object

Represents an event returned by channel.receive(), as a result of another channel instance requesting a state from this channel. Other channel has to invoke channel.getState() indicating intent of state retrieval.

Allows applications using a channel in a pull mode to receive StreamingGetStateEvent event and thus provide state to requsting channel instance. Channels have to be configured with STREAMING_STATE_TRANSFER protocol rather than the default STATE_TRANSFER protocol in order to receive this event

The following code demonstrates how to pull events from a channel, processing StreamingGetStateEvent and sending hypothetical state through OutputStream reference.

  Object obj=channel.receive(0);
  if(obj instanceof StreamingGetStateEvent) {
        StreamingGetStateEvent evt=(StreamingGetStateEvent)obj;
        OutputStream oos = null;
                try {                   
                        oos = new ObjectOutputStream(evt.getArg());                     
                        oos.writeObject(state);   
                oos.flush();
                } catch (Exception e) {} 
                finally
                {
                        try {                           
                                oos.close();
                        } catch (IOException e) {
                                System.err.println(e);
                        }
                }                
   }
 

Since:

2.4

Author:

Vladimir Blagojevic

See Also:

JChannel.getState(Address, long), org.jgroups.StreamingMessageListener#getState(OutputStream)

Constructor Summary

Constructors

Constructor	Description
StreamingGetStateEvent(java.io.OutputStream os, java.lang.String state_id)

Method Summary

Modifier and Type	Method	Description
java.io.OutputStream	getArg()	Returns OutputStream used for writing of a state.
java.lang.String	getStateId()	Returns id of the partial state if partial state was requested.

Methods inherited from class java.lang.Object

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

Constructor Detail

StreamingGetStateEvent

public StreamingGetStateEvent(java.io.OutputStream os,
                              java.lang.String state_id)

Method Detail

getArg

public java.io.OutputStream getArg()

Returns OutputStream used for writing of a state.

Returns:

the OutputStream

getStateId

public java.lang.String getStateId()

Returns id of the partial state if partial state was requested. If full state transfer was requested this method will return null.

Returns:

partial state id

See Also:

JChannel.getState(Address, long), JChannel.getState(Address, String, long)