org.apache.curator.framework.recipes.nodes
Class PersistentEphemeralNode

java.lang.Object
  org.apache.curator.framework.recipes.nodes.PersistentEphemeralNode

All Implemented Interfaces:

Closeable

public class PersistentEphemeralNode
extends Object
implements Closeable

A persistent ephemeral node is an ephemeral node that attempts to stay present in ZooKeeper, even through connection and session interruptions.

Thanks to bbeck (https://github.com/bbeck) for the initial coding and design

Nested Class Summary

static class

PersistentEphemeralNode.Mode The mode for node creation

Constructor Summary

PersistentEphemeralNode(org.apache.curator.framework.CuratorFramework client, PersistentEphemeralNode.Mode mode, String basePath, byte[] data)

Method Summary

void	close()
String	getActualPath() Returns the currently set path or null if the node does not exist
void	setData(byte[] data) Set data that ephemeral node should set in ZK also writes the data to the node
void	start() You must call start() to initiate the persistent ephemeral node.
boolean	waitForInitialCreate(long timeout, TimeUnit unit) Block until the either initial node creation initiated by start() succeeds or the timeout elapses.

Methods inherited from class java.lang.Object

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

Constructor Detail

PersistentEphemeralNode

public PersistentEphemeralNode(org.apache.curator.framework.CuratorFramework client,
                               PersistentEphemeralNode.Mode mode,
                               String basePath,
                               byte[] data)

Parameters:

client - client instance

mode - creation/protection mode

basePath - the base path for the node

data - data for the node

Method Detail

start

public void start()

You must call start() to initiate the persistent ephemeral node. An attempt to create the node in the background will be started

waitForInitialCreate

public boolean waitForInitialCreate(long timeout,
                                    TimeUnit unit)
                             throws InterruptedException

Block until the either initial node creation initiated by start() succeeds or the timeout elapses.

Parameters:

timeout - the maximum time to wait

unit - time unit

Returns:

if the node was created before timeout

Throws:

InterruptedException - if the thread is interrupted

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Throws:

IOException

getActualPath

public String getActualPath()

Returns the currently set path or null if the node does not exist

Returns:

node path or null

setData

public void setData(byte[] data)
             throws Exception

Set data that ephemeral node should set in ZK also writes the data to the node

Parameters:

data - new data value

Throws:

Exception - errors