org.adroitlogic.x.clustering.util

Class CuratorUtils

java.lang.Object

org.adroitlogic.x.clustering.util.CuratorUtils

public class CuratorUtils
extends Object

Utility class to be used when working with Apache Curator.

Since:

17.01

Author:

Imesha Sudasingha

Method Summary

Modifier and Type	Method and Description
static void	createIfNotExists(org.apache.curator.framework.CuratorFramework client, String path) Creates a ZNode in the given path if a ZNode doesn't already exist there
static void	createZNodeIfNotExists(org.apache.curator.framework.CuratorFramework curatorFramework, String zNodePath, org.apache.zookeeper.CreateMode mode) Create a ZNode in the given path if not exists.
static boolean	deleteIfExists(org.apache.curator.framework.CuratorFramework client, String path)
static int	fixCommandVersionForExternalUse(int commandVersion) Fix the 0-based indexing mismatch of the version number for external uses.
static int	fixCommandVersionForInternalUse(int commandVersion)
static String	generateCommandSuffix(int version) Generate the command suffix, this is in general the patter being used by the zookeeper sequential nodes.
static int	getCommandVersionFromZNodeName(String path) Get the child version (the sequential number appended to sequential nodes) of a given sequential node
static String	getIfExists(org.apache.curator.framework.CuratorFramework client, String path) Gets the String value of the data in the given znode path
static void	move(org.apache.curator.framework.CuratorFramework client, String from, String to) Moves a given ZNode specified by the path

Methods inherited from class java.lang.Object

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

Method Detail

createZNodeIfNotExists

public static void createZNodeIfNotExists(org.apache.curator.framework.CuratorFramework curatorFramework,
                                          String zNodePath,
                                          org.apache.zookeeper.CreateMode mode)

Create a ZNode in the given path if not exists.

Parameters:

curatorFramework - CuratorFramework client

zNodePath - the path in which the ZNode to be created

mode - the create mode of the zookeeper node

fixCommandVersionForExternalUse

public static int fixCommandVersionForExternalUse(int commandVersion)

Fix the 0-based indexing mismatch of the version number for external uses. Usually, the CommandProcessor require this method to convert the internal version numbers into the external indexing convention.

Parameters:

commandVersion - internally used version number

Returns:

fixed version number for external usage. i.e: for logging

fixCommandVersionForInternalUse

public static int fixCommandVersionForInternalUse(int commandVersion)

Parameters:

commandVersion - externally provided version number

Returns:

fixed version number

See Also:

fixCommandVersionForExternalUse(int)

getIfExists

public static String getIfExists(org.apache.curator.framework.CuratorFramework client,
                                 String path)
                          throws Exception

Gets the String value of the data in the given znode path

Parameters:

client - CuratorFramework client

path - ZNode path to be checked

Returns:

ZNode's data as a string or null

Throws:

Exception - zookeeper errors and etc

deleteIfExists

public static boolean deleteIfExists(org.apache.curator.framework.CuratorFramework client,
                                     String path)
                              throws Exception

Throws:

Exception

createIfNotExists

public static void createIfNotExists(org.apache.curator.framework.CuratorFramework client,
                                     String path)
                              throws Exception

Creates a ZNode in the given path if a ZNode doesn't already exist there

Parameters:

client - CuratorFramework client

path - path in which the znode has to be created

Throws:

Exception - zookeeper errors

generateCommandSuffix

public static String generateCommandSuffix(int version)

Generate the command suffix, this is in general the patter being used by the zookeeper sequential nodes. The patter contains a 10 characters and denotes a number in general. For example the command suffix for the version 3 is "0000000003" and the command suffix for the version 16 is "0000000016" and so forth.

Parameters:

version - to be converted to 10 digit number String representation

Returns:

10 digit String representation of the version

getCommandVersionFromZNodeName

public static int getCommandVersionFromZNodeName(String path)

Get the child version (the sequential number appended to sequential nodes) of a given sequential node

Parameters:

path - sequential node path

Returns:

child version (CVersion)

move

public static void move(org.apache.curator.framework.CuratorFramework client,
                        String from,
                        String to)
                 throws Exception

Moves a given ZNode specified by the path

from

to the ZNode path specified by

to

.

Parameters:

client - CuratorFramework instance

from - The path of the ZNode which is to be moved

to - The destination ZNode path

Throws:

Exception - Zookeeper errors ...