org.apache.twill.zookeeper

Interface ZKClient

All Known Subinterfaces:

ZKClientService

All Known Implementing Classes:

AbstractZKClient, ForwardingZKClient, ForwardingZKClientService

public interface ZKClient

A ZooKeeper client that provides asynchronous zookeeper operations.

Method Summary

Modifier and Type	Method and Description
Cancellable	addConnectionWatcher(org.apache.zookeeper.Watcher watcher) Adds a Watcher that will be called whenever connection state change.
OperationFuture<String>	create(String path, byte[] data, org.apache.zookeeper.CreateMode createMode) Creates a path in zookeeper.
OperationFuture<String>	create(String path, byte[] data, org.apache.zookeeper.CreateMode createMode, boolean createParent) Creates a path in zookeeper.
OperationFuture<String>	create(String path, byte[] data, org.apache.zookeeper.CreateMode createMode, boolean createParent, Iterable<org.apache.zookeeper.data.ACL> acl) Creates a path in zookeeper, with given data and create mode.
OperationFuture<String>	create(String path, byte[] data, org.apache.zookeeper.CreateMode createMode, Iterable<org.apache.zookeeper.data.ACL> acl) Creates a path in zookeeper.
OperationFuture<String>	delete(String path) Deletes the node of the given path without matching version.
OperationFuture<String>	delete(String deletePath, int version) Deletes the node of the given path that match the given version.
OperationFuture<org.apache.zookeeper.data.Stat>	exists(String path) Checks if the path exists.
OperationFuture<org.apache.zookeeper.data.Stat>	exists(String path, org.apache.zookeeper.Watcher watcher) Checks if the given path exists and leave a watcher on the node for watching creation/deletion/data changes on the node.
OperationFuture<ACLData>	getACL(String path) Retrieves the Stat and ACL being set at the given path.
OperationFuture<NodeChildren>	getChildren(String path) Gets the list of children nodes under the given path.
OperationFuture<NodeChildren>	getChildren(String path, org.apache.zookeeper.Watcher watcher) Gets the list of children nodes under the given path and leave a watcher on the node for watching node deletion and children nodes creation/deletion.
String	getConnectString() Returns the connection string used for connecting to Zookeeper.
OperationFuture<NodeData>	getData(String path) Gets the data stored in the given path.
OperationFuture<NodeData>	getData(String path, org.apache.zookeeper.Watcher watcher) Gets the data stored in the given path and leave a watcher on the node for watching deletion/data changes on the node.
Long	getSessionId() Returns the current Zookeeper session ID of this client.
OperationFuture<org.apache.zookeeper.data.Stat>	setACL(String path, Iterable<org.apache.zookeeper.data.ACL> acl) Sets the ACL of the given path if the path exists.
OperationFuture<org.apache.zookeeper.data.Stat>	setACL(String path, Iterable<org.apache.zookeeper.data.ACL> acl, int version) Sets the ACL of the given path if the path exists and version matched.
OperationFuture<org.apache.zookeeper.data.Stat>	setData(String path, byte[] data) Sets the data for the given path without matching version.
OperationFuture<org.apache.zookeeper.data.Stat>	setData(String dataPath, byte[] data, int version) Sets the data for the given path that match the given version.

Method Detail

getSessionId

Long getSessionId()

Returns the current Zookeeper session ID of this client. If this ZKClient is not connected, null is returned.

getConnectString

String getConnectString()

Returns the connection string used for connecting to Zookeeper.

addConnectionWatcher

Cancellable addConnectionWatcher(org.apache.zookeeper.Watcher watcher)

Adds a Watcher that will be called whenever connection state change.

Parameters:

watcher - The watcher to set.

Returns:

A Cancellable for removing the watcher

create

OperationFuture<String> create(String path,
                               @Nullable
                               byte[] data,
                               org.apache.zookeeper.CreateMode createMode)

Creates a path in zookeeper. Same as calling create(path, data, createMode, true).

See Also:

create(String, byte[], org.apache.zookeeper.CreateMode, boolean)

create

OperationFuture<String> create(String path,
                               @Nullable
                               byte[] data,
                               org.apache.zookeeper.CreateMode createMode,
                               boolean createParent)

Creates a path in zookeeper. Same as calling create(path, data, createMode, createParent, ZooDefs.Ids.OPEN_ACL_UNSAFE)

See Also:

create(String, byte[], org.apache.zookeeper.CreateMode, boolean, Iterable)

create

OperationFuture<String> create(String path,
                               @Nullable
                               byte[] data,
                               org.apache.zookeeper.CreateMode createMode,
                               Iterable<org.apache.zookeeper.data.ACL> acl)

Creates a path in zookeeper. Same as calling create(path, data, createMode, true, acl)

See Also:

create(String, byte[], org.apache.zookeeper.CreateMode, boolean, Iterable)

create

OperationFuture<String> create(String path,
                               @Nullable
                               byte[] data,
                               org.apache.zookeeper.CreateMode createMode,
                               boolean createParent,
                               Iterable<org.apache.zookeeper.data.ACL> acl)

Creates a path in zookeeper, with given data and create mode.

Parameters:

path - Path to be created

data - Data to be stored in the node, or null if no data to store.

createMode - The CreateMode for the node.

createParent - If true and parent nodes are missing, it will create all parent nodes as normal persistent node with the ACL ZooDefs.Ids.OPEN_ACL_UNSAFE before creating the request node.

acl - Set of ACL to be set for the node being created.

Returns:

A OperationFuture that will be completed when the creation is done. If there is error during creation, it will be reflected as error in the future.

exists

OperationFuture<org.apache.zookeeper.data.Stat> exists(String path)

Checks if the path exists. Same as calling exists(path, null).

See Also:

exists(String, org.apache.zookeeper.Watcher)

exists

OperationFuture<org.apache.zookeeper.data.Stat> exists(String path,
                                                       @Nullable
                                                       org.apache.zookeeper.Watcher watcher)

Checks if the given path exists and leave a watcher on the node for watching creation/deletion/data changes on the node.

Parameters:

path - The path to check for existence.

watcher - Watcher for watching changes, or null if no watcher to set.

Returns:

A OperationFuture that will be completed when the exists check is done. If the path does exists, the node Stat is set into the future. If the path doesn't exists, a null value is set into the future.

getChildren

OperationFuture<NodeChildren> getChildren(String path)

Gets the list of children nodes under the given path. Same as calling getChildren(path, null).

See Also:

getChildren(String, org.apache.zookeeper.Watcher)

getChildren

OperationFuture<NodeChildren> getChildren(String path,
                                          @Nullable
                                          org.apache.zookeeper.Watcher watcher)

Gets the list of children nodes under the given path and leave a watcher on the node for watching node deletion and children nodes creation/deletion.

Parameters:

path - The path to fetch for children nodes

watcher - Watcher for watching changes, or null if no watcher to set.

Returns:

A OperationFuture that will be completed when the getChildren call is done, with the result given as NodeChildren. If there is error, it will be reflected as error in the future.

getData

OperationFuture<NodeData> getData(String path)

Gets the data stored in the given path. Same as calling getData(path, null).

getData

OperationFuture<NodeData> getData(String path,
                                  @Nullable
                                  org.apache.zookeeper.Watcher watcher)

Gets the data stored in the given path and leave a watcher on the node for watching deletion/data changes on the node.

Parameters:

path - The path to get data from.

watcher - Watcher for watching changes, or null if no watcher to set.

Returns:

A OperationFuture that will be completed when the getData call is done, with the result given as NodeData. If there is error, it will be reflected as error in the future.

setData

OperationFuture<org.apache.zookeeper.data.Stat> setData(String path,
                                                        byte[] data)

Sets the data for the given path without matching version. Same as calling setData(path, data, -1).

setData

OperationFuture<org.apache.zookeeper.data.Stat> setData(String dataPath,
                                                        byte[] data,
                                                        int version)

Sets the data for the given path that match the given version. If the version given is -1, it matches any version.

Parameters:

dataPath - The path to set data to.

data - Data to be set.

version - Matching version.

Returns:

A OperationFuture that will be completed when the setData call is done, with node Stat given as the future result. If there is error, it will be reflected as error in the future.

delete

OperationFuture<String> delete(String path)

Deletes the node of the given path without matching version. Same as calling delete(path, -1).

See Also:

delete(String, int)

delete

OperationFuture<String> delete(String deletePath,
                               int version)

Deletes the node of the given path that match the given version. If the version given is -1, it matches any version.

Parameters:

deletePath - The path to set data to.

version - Matching version.

Returns:

A OperationFuture that will be completed when the setData call is done, with node path given as the future result. If there is error, it will be reflected as error in the future.

getACL

OperationFuture<ACLData> getACL(String path)

Retrieves the Stat and ACL being set at the given path.

Parameters:

path - The path to get information from.

Returns:

A OperationFuture that will be completed when the getACL call is done, with the result given as ACLData. If there is error, it will be reflected as error in the future.

setACL

OperationFuture<org.apache.zookeeper.data.Stat> setACL(String path,
                                                       Iterable<org.apache.zookeeper.data.ACL> acl)

Sets the ACL of the given path if the path exists. Same as calling setACL(path, acl, -1)

See Also:

setACL(String, Iterable, int)

setACL

OperationFuture<org.apache.zookeeper.data.Stat> setACL(String path,
                                                       Iterable<org.apache.zookeeper.data.ACL> acl,
                                                       int version)

Sets the ACL of the given path if the path exists and version matched.

Parameters:

path - The path to have ACL being set.

acl - ACL to set to.

version - Version of the node.

Returns:

A OperationFuture that will be completed when the setACL call is done, with the node Stat available as the future result. If there is error, it will be reflected as error in the future.