Package org.apache.curator.framework.state

Enum ConnectionState

java.lang.Object

java.lang.Enum<ConnectionState>

org.apache.curator.framework.state.ConnectionState

public enum ConnectionState
extends java.lang.Enum<ConnectionState>

Represents state changes in the connection to ZK

Enum Constant Summary

Enum Constants

Enum Constant	Description
CONNECTED	Sent for the first successful connection to the server.
LOST	Curator will set the LOST state when it believes that the ZooKeeper session has expired.
READ_ONLY	The connection has gone into read-only mode.
RECONNECTED	A suspended, lost, or read-only connection has been re-established
SUSPENDED	There has been a loss of connection.

Method Summary

Modifier and Type	Method	Description
abstract boolean	isConnected()	Check if this state indicates that Curator has a connection to ZooKeeper
static ConnectionState	valueOf(java.lang.String name)	Returns the enum constant of this type with the specified name.
static ConnectionState[]	values()	Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

CONNECTED

public static final ConnectionState CONNECTED

Sent for the first successful connection to the server. NOTE: You will only get one of these messages for any CuratorFramework instance.

SUSPENDED

public static final ConnectionState SUSPENDED

There has been a loss of connection. Leaders, locks, etc. should suspend until the connection is re-established.

RECONNECTED

public static final ConnectionState RECONNECTED

A suspended, lost, or read-only connection has been re-established

LOST

public static final ConnectionState LOST

Curator will set the LOST state when it believes that the ZooKeeper session has expired. ZooKeeper connections have a session. When the session expires, clients must take appropriate action. In Curator, this is complicated by the fact that Curator internally manages the ZooKeeper connection. Curator will set the LOST state when any of the following occurs: a) ZooKeeper returns a Watcher.Event.KeeperState.Expired or KeeperException.Code.SESSIONEXPIRED; b) Curator closes the internally managed ZooKeeper instance; c) The session timeout elapses during a network partition.

NOTE: see CuratorFrameworkFactory.Builder.connectionHandlingPolicy(ConnectionHandlingPolicy) for an important note about a change in meaning to LOST since 3.0.0

READ_ONLY

public static final ConnectionState READ_ONLY

The connection has gone into read-only mode. This can only happen if you pass true for CuratorFrameworkFactory.Builder.canBeReadOnly(). See the ZooKeeper doc regarding read only connections: http://wiki.apache.org/hadoop/ZooKeeper/GSoCReadOnlyMode. The connection will remain in read only mode until another state change is sent.

Method Detail

values

public static ConnectionState[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (ConnectionState c : ConnectionState.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static ConnectionState valueOf(java.lang.String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

java.lang.IllegalArgumentException - if this enum type has no constant with the specified name

java.lang.NullPointerException - if the argument is null

isConnected

public abstract boolean isConnected()

Check if this state indicates that Curator has a connection to ZooKeeper

Returns:

True if connected, false otherwise