Package org.apache.curator.framework.recipes.nodes

Class PersistentNode

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable
    Direct Known Subclasses:
    PersistentEphemeralNode
    public class PersistentNode
extends java.lang.Object
implements java.io.Closeable

    A persistent node is a 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

    • Constructor Summary

      Constructors 
      Constructor Description
      PersistentNode​(org.apache.curator.framework.CuratorFramework givenClient, org.apache.zookeeper.CreateMode mode, boolean useProtection, java.lang.String basePath, byte[] initData)  
      PersistentNode​(org.apache.curator.framework.CuratorFramework givenClient, org.apache.zookeeper.CreateMode mode, boolean useProtection, java.lang.String basePath, byte[] initData, long ttl)  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void close()  
      protected void deleteNode()  
      java.lang.String getActualPath()
      Returns the currently set path or null if the node does not exist
      byte[] getData()
      Return the current value of our data
      org.apache.curator.framework.listen.ListenerContainer<PersistentNodeListener> getListenable()
      Returns the listenable
      void setData​(byte[] data)
      Set data that node should set in ZK also writes the data to the node.
      void start()
      You must call start() to initiate the persistent node.
      boolean waitForInitialCreate​(long timeout, java.util.concurrent.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

      • PersistentNode

        public PersistentNode​(org.apache.curator.framework.CuratorFramework givenClient,
                      org.apache.zookeeper.CreateMode mode,
                      boolean useProtection,
                      java.lang.String basePath,
                      byte[] initData)
        Parameters:
        givenClient - client instance
        mode - creation mode
        useProtection - if true, call CreateBuilderMain.withProtection()
        basePath - the base path for the node
        initData - data for the node

      • PersistentNode

        public PersistentNode​(org.apache.curator.framework.CuratorFramework givenClient,
                      org.apache.zookeeper.CreateMode mode,
                      boolean useProtection,
                      java.lang.String basePath,
                      byte[] initData,
                      long ttl)
        Parameters:
        givenClient - client instance
        mode - creation mode
        useProtection - if true, call CreateBuilderMain.withProtection()
        basePath - the base path for the node
        initData - data for the node
        ttl - for ttl modes, the ttl to use

    • Method Detail

      • start

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

      • waitForInitialCreate

        public boolean waitForInitialCreate​(long timeout,
                                    java.util.concurrent.TimeUnit unit)
                             throws java.lang.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:
        java.lang.InterruptedException - if the thread is interrupted

      • close

        public void close()
           throws java.io.IOException
        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface java.io.Closeable
        Throws:
        java.io.IOException

      • getListenable

        public org.apache.curator.framework.listen.ListenerContainer<PersistentNodeListener> getListenable()
        Returns the listenable
        Returns:
        listenable

      • getActualPath

        public java.lang.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 java.lang.Exception
        Set data that node should set in ZK also writes the data to the node. NOTE: it is an error to call this method after start() but before the initial create has completed. Use waitForInitialCreate(long, TimeUnit) to ensure initial creation.
        Parameters:
        data - new data value
        Throws:
        java.lang.Exception - errors

      • getData

        public byte[] getData()
        Return the current value of our data
        Returns:
        our data

      • deleteNode

        protected void deleteNode()
                   throws java.lang.Exception
        Throws:
        java.lang.Exception