Package org.jgroups.blocks

Class ReplicatedHashtable

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Cloneable, java.util.Map, MembershipListener, MessageListener
    public class ReplicatedHashtable
extends java.util.Hashtable
implements MessageListener, MembershipListener
    Deprecated.
    Use ReplicatedHashMap instead
    Provides the abstraction of a java.util.Hashtable that is replicated at several locations. Any change to the hashtable (clear, put, remove etc) will transparently be propagated to all replicas in the group. All read-only methods will always access the local replica.

    Both keys and values added to the hashtable must be serializable, the reason being that they will be sent across the network to all replicas of the group. Having said this, it is now for example possible to add RMI remote objects to the hashtable as they are derived from java.rmi.server.RemoteObject which in turn is serializable. This allows to lookup shared distributed objects by their name and invoke methods on them, regardless of one's onw location. A ReplicatedHashtable thus allows to implement a distributed naming service in just a couple of lines.

    An instance of this class will contact an existing member of the group to fetch its initial state.

    Contrary to DistributedHashtable, this class does not make use of RpcDispatcher (and RequestCorrelator) but uses plain asynchronous messages instead.

    Author:
    Bela Ban, Alfonso Olias-Sanz
    See Also:
    Serialized Form

    • Field Detail

      • log

        protected final transient org.apache.commons.logging.Log log
        Deprecated.

    • Method Detail

      • stateTransferRunning

        public boolean stateTransferRunning()
        Deprecated.

      • getLocalAddress

        public Address getLocalAddress()
        Deprecated.

      • getChannel

        public Channel getChannel()
        Deprecated.

      • put

        public java.lang.Object put​(java.lang.Object key,
                            java.lang.Object value)
        Deprecated.
        Maps the specified key to the specified value in the hashtable. Neither of both parameters can be null
        Specified by:
        put in interface java.util.Map
        Overrides:
        put in class java.util.Hashtable
        Parameters:
        key - - the hashtable key
        value - - the value
        Returns:
        the previous value of the specified key in this hashtable, or null if it did not have one

      • putAll

        public void putAll​(java.util.Map m)
        Deprecated.
        Copies all of the mappings from the specified Map to this Hashtable These mappings will replace any mappings that this Hashtable had for any of the keys currently in the specified Map.
        Specified by:
        putAll in interface java.util.Map
        Overrides:
        putAll in class java.util.Hashtable
        Parameters:
        m - - Mappings to be stored in this map

      • clear

        public void clear()
        Deprecated.
        Clears this hashtable so that it contains no keys
        Specified by:
        clear in interface java.util.Map
        Overrides:
        clear in class java.util.Hashtable

      • remove

        public java.lang.Object remove​(java.lang.Object key)
        Deprecated.
        Removes the key (and its corresponding value) from the Hashtable.
        Specified by:
        remove in interface java.util.Map
        Overrides:
        remove in class java.util.Hashtable
        Parameters:
        key - - the key to be removed.
        Returns:
        the value to which the key had been mapped in this hashtable, or null if the key did not have a mapping.

      • _putAll

        public void _putAll​(java.util.Map m)
        Deprecated.
        See Also:
        Map.putAll(java.util.Map)

      • getState

        public byte[] getState()
        Deprecated.
        Description copied from interface: MessageListener
        Answers the group state; e.g., when joining.
        Specified by:
        getState in interface MessageListener
        Returns:
        byte[]

      • setState

        public void setState​(byte[] new_state)
        Deprecated.
        Description copied from interface: MessageListener
        Sets the group state; e.g., when joining.
        Specified by:
        setState in interface MessageListener

      • viewAccepted

        public void viewAccepted​(View new_view)
        Deprecated.
        Description copied from interface: MembershipListener
        Called when a change in membership has occurred. No long running actions or sending of messages should be done in this callback. If some long running action needs to be performed, it should be done in a separate thread.

        Note that on reception of the first view (a new member just joined), the channel will not yet be in the connected state. This only happens when Channel.connect(String) returns.

        Specified by:
        viewAccepted in interface MembershipListener

      • suspect

        public void suspect​(Address suspected_mbr)
        Deprecated.
        Called when a member is suspected
        Specified by:
        suspect in interface MembershipListener

      • block

        public void block()
        Deprecated.
        Block sending and receiving of messages until ViewAccepted is called
        Specified by:
        block in interface MembershipListener