AckExtension (CometD :: Java 4.0.9 API)

java.lang.Object
- org.cometd.client.ext.AckExtension

All Implemented Interfaces:

ClientSession.Extension
```
public class AckExtension
extends Object
implements ClientSession.Extension
```
This client-side extension enables the client to acknowledge to the server the messages that the client has received.

For the acknowledgement to work, the server must be configured with the correspondent server-side ack extension. If both client and server support the ack extension, then the ack functionality will take place automatically. By enabling this extension, all messages arriving from the server will arrive via the long poll, so the comet communication will be slightly chattier. The fact that all messages will return via long poll means also that the messages will arrive with total order, which is not guaranteed if messages can arrive via both long poll and normal response. Messages are not acknowledged one by one, but instead a group of messages is acknowledged when long poll returns.

Nested Class Summary
- Nested classes/interfaces inherited from interface org.cometd.bayeux.client.ClientSession.Extension
  ClientSession.Extension.Adapter

Field Summary

Fields
Modifier and Type Field Description

static String ACK_FIELD

Constructor Summary

Constructors
Constructor Description

AckExtension()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`rcvMeta(ClientSession session, Message.Mutable message)`	Callback method invoked every time a meta message is received.
`boolean`	`sendMeta(ClientSession session, Message.Mutable message)`	Callback method invoked every time a meta message is being sent.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.cometd.bayeux.client.ClientSession.Extension
incoming, outgoing, rcv, send

- Field Detail
  - ACK_FIELD
```
public static final String ACK_FIELD
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - AckExtension
```
public AckExtension()
```
- Method Detail
  - rcvMeta
```
public boolean rcvMeta(ClientSession session,
                       Message.Mutable message)
```
    Description copied from interface: ClientSession.Extension
    
    Callback method invoked every time a meta message is received.
    
    Specified by:
    
    rcvMeta in interface ClientSession.Extension
    
    Parameters:
    
    session - the session object that is receiving the meta message
    
    message - the meta message received
    
    Returns:
    
    true if message processing should continue, false if it should stop
  - sendMeta
```
public boolean sendMeta(ClientSession session,
                        Message.Mutable message)
```
    Description copied from interface: ClientSession.Extension
    
    Callback method invoked every time a meta message is being sent.
    
    Specified by:
    
    sendMeta in interface ClientSession.Extension
    
    Parameters:
    
    session - the session object that is sending the message
    
    message - the meta message being sent
    
    Returns:
    
    true if message processing should continue, false if it should stop