org.apache.hadoop.hbase.zookeeper

Class ZooKeeperListener

java.lang.Object

org.apache.hadoop.hbase.zookeeper.ZooKeeperListener

Direct Known Subclasses:

ReplicationTrackerZKImpl.OtherRegionServerWatcher, ReplicationTrackerZKImpl.PeersWatcher, ZKLeaderManager, ZooKeeperNodeTracker

@InterfaceAudience.Private
public abstract class ZooKeeperListener
extends Object

Base class for internal listeners of ZooKeeper events. The ZooKeeperWatcher for a process will execute the appropriate methods of implementations of this class. In order to receive events from the watcher, every listener must register itself via ZooKeeperWatcher.registerListener(org.apache.hadoop.hbase.zookeeper.ZooKeeperListener). Subclasses need only override those methods in which they are interested. Note that the watcher will be blocked when invoking methods in listeners so they must not be long-running.

Field Summary

Fields

Modifier and Type	Field and Description
protected ZooKeeperWatcher	watcher

Constructor Summary

Constructors

Constructor and Description
ZooKeeperListener(ZooKeeperWatcher watcher) Construct a ZooKeeper event listener.

Method Summary

Methods

Modifier and Type	Method and Description
ZooKeeperWatcher	getWatcher()
void	nodeChildrenChanged(String path) Called when an existing node has a child node added or removed.
void	nodeCreated(String path) Called when a new node has been created.
void	nodeDataChanged(String path) Called when an existing node has changed data.
void	nodeDeleted(String path) Called when a node has been deleted

Methods inherited from class java.lang.Object

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

Field Detail

watcher

protected ZooKeeperWatcher watcher

Constructor Detail

ZooKeeperListener

public ZooKeeperListener(ZooKeeperWatcher watcher)

Construct a ZooKeeper event listener.

Method Detail

nodeCreated

public void nodeCreated(String path)

Called when a new node has been created.

Parameters:

path - full path of the new node

nodeDeleted

public void nodeDeleted(String path)

Called when a node has been deleted

Parameters:

path - full path of the deleted node

nodeDataChanged

public void nodeDataChanged(String path)

Called when an existing node has changed data.

Parameters:

path - full path of the updated node

nodeChildrenChanged

public void nodeChildrenChanged(String path)

Called when an existing node has a child node added or removed.

Parameters:

path - full path of the node whose children have changed

getWatcher

public ZooKeeperWatcher getWatcher()

Returns:

The watcher associated with this listener