Package org.apache.zookeeper

Class ZKUtil

java.lang.Object

org.apache.zookeeper.ZKUtil

public class ZKUtil
extends Object

Constructor Summary

Constructors

Constructor	Description
ZKUtil()

Method Summary

Modifier and Type	Method	Description
static String	aclToString(List<ACL> acls)
static void	deleteRecursive(ZooKeeper zk, String pathRoot)	Same as deleteRecursive(org.apache.zookeeper.ZooKeeper, java.lang.String, int) kept here for compatibility with 3.5 clients.
static boolean	deleteRecursive(ZooKeeper zk, String pathRoot, int batchSize)	Recursively delete the node with the given path.
static void	deleteRecursive(ZooKeeper zk, String pathRoot, AsyncCallback.VoidCallback cb, Object ctx)	Recursively delete the node with the given path.
static String	getPermString(int perms)
static List<String>	listSubTreeBFS(ZooKeeper zk, String pathRoot)	BFS Traversal of the system under pathRoot, with the entries in the list, in the same order as that of the traversal.
static String	validateFileInput(String filePath)
static void	visitSubTreeDFS(ZooKeeper zk, String path, boolean watch, AsyncCallback.StringCallback cb)	Visits the subtree with root as given path and calls the passed callback with each znode found during the search.

Methods inherited from class java.lang.Object

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

Constructor Detail

ZKUtil

public ZKUtil()

Method Detail

deleteRecursive

public static boolean deleteRecursive(ZooKeeper zk,
                                      String pathRoot,
                                      int batchSize)
                               throws InterruptedException,
                                      KeeperException

Recursively delete the node with the given path.

Important: All versions, of all nodes, under the given node are deleted.

If there is an error with deleting one of the sub-nodes in the tree, this operation would abort and would be the responsibility of the app to handle the same.

Parameters:

zk - Zookeeper client

pathRoot - path to be deleted

batchSize - number of delete operations to be submitted in one call. batchSize is also used to decide sync and async delete API invocation. If batchSize>0 then async otherwise sync delete API is invoked. batchSize>0 gives better performance. batchSize<=0 scenario is handled to preserve backward compatibility.

Returns:

true if given node and all its sub nodes are deleted successfully otherwise false

Throws:

IllegalArgumentException - if an invalid path is specified

InterruptedException

KeeperException

deleteRecursive

public static void deleteRecursive(ZooKeeper zk,
                                   String pathRoot)
                            throws InterruptedException,
                                   KeeperException

Same as deleteRecursive(org.apache.zookeeper.ZooKeeper, java.lang.String, int) kept here for compatibility with 3.5 clients.

Throws:

InterruptedException

KeeperException

Since:

3.6.1

deleteRecursive

public static void deleteRecursive(ZooKeeper zk,
                                   String pathRoot,
                                   AsyncCallback.VoidCallback cb,
                                   Object ctx)
                            throws InterruptedException,
                                   KeeperException

Recursively delete the node with the given path. (async version).

Important: All versions, of all nodes, under the given node are deleted.

If there is an error with deleting one of the sub-nodes in the tree, this operation would abort and would be the responsibility of the app to handle the same.

Parameters:

zk - the zookeeper handle

pathRoot - the path to be deleted

cb - call back method

ctx - the context the callback method is called with

Throws:

IllegalArgumentException - if an invalid path is specified

InterruptedException

KeeperException

validateFileInput

public static String validateFileInput(String filePath)

Parameters:

filePath - the file path to be validated

Returns:

Returns null if valid otherwise error message

listSubTreeBFS

public static List<String> listSubTreeBFS(ZooKeeper zk,
                                          String pathRoot)
                                   throws KeeperException,
                                          InterruptedException

BFS Traversal of the system under pathRoot, with the entries in the list, in the same order as that of the traversal.

Important: This is not an atomic snapshot of the tree ever, but the state as it exists across multiple RPCs from zkClient to the ensemble. For practical purposes, it is suggested to bring the clients to the ensemble down (i.e. prevent writes to pathRoot) to 'simulate' a snapshot behavior.

Parameters:

zk - the zookeeper handle

pathRoot - The znode path, for which the entire subtree needs to be listed.

Throws:

InterruptedException

KeeperException

visitSubTreeDFS

public static void visitSubTreeDFS(ZooKeeper zk,
                                   String path,
                                   boolean watch,
                                   AsyncCallback.StringCallback cb)
                            throws KeeperException,
                                   InterruptedException

Visits the subtree with root as given path and calls the passed callback with each znode found during the search. It performs a depth-first, pre-order traversal of the tree.

Important: This is not an atomic snapshot of the tree ever, but the state as it exists across multiple RPCs from zkClient to the ensemble. For practical purposes, it is suggested to bring the clients to the ensemble down (i.e. prevent writes to pathRoot) to 'simulate' a snapshot behavior.

Throws:

KeeperException

InterruptedException

getPermString

public static String getPermString(int perms)

Parameters:

perms - ACL permissions

Returns:

string representation of permissions

aclToString

public static String aclToString(List<ACL> acls)