Package org.jgroups

Class Membership

java.lang.Object
org.jgroups.Membership
public class Membership extends Object
Represents a membership of a cluster group. Membership is not exposed to clients and is used by JGroups internally. The membership object holds a list of Address objects that are in the same membership. Each unique address can only exist once.
Since:
2.0

  • Field Details

  • Constructor Details

    • Membership

      public Membership()
      Creates a member ship object with zero members

    • Membership

      public Membership(Collection<Address> initial_members)
      Creates a Membership with a given initial members. The Address references are copied out of the list, so that the list passed in as parameters is not the same reference as the list that the membership class uses
      Parameters:
      initial_members - a list of members that belong to this membership

    • Membership

      public Membership(Address... initial_members)

  • Method Details

    • getMembers

      public List<Address> getMembers()
      Returns a copy (clone) of the members in this membership. The vector returned is immutable in reference to this object. ie, modifying the vector that is being returned in this method will not modify this membership object.
      Returns:
      a list of members

    • add

      public Membership add(Address new_member)
      Adds a new member to this membership. If the member already exist (Address.equals(Object) returns true then the member will not be added to the membership

    • add

      public Membership add(Address... mbrs)

    • add

      public Membership add(Collection<Address> v)
      Adds a list of members to this membership
      Parameters:
      v - - a listof addresses
      Throws:
      ClassCastException - if v contains objects that don't implement the Address interface

    • remove

      public Membership remove(Address old_member)
      Removes a member from the membership. If this member doesn't exist, no action will be performed on the existing membership
      Parameters:
      old_member - The member to be removed

    • remove

      public Membership remove(Collection<Address> v)
      Removes all the members contained in v from this membership
      Parameters:
      v - a list of all the members to be removed

    • retainAll

      public Membership retainAll(Collection<Address> v)

    • clear

      public Membership clear()
      Removes all the members from this membership

    • set

      public Membership set(Collection<Address> v)
      Clears the membership and adds all members of v This method will clear out all the old members of this membership by invoking the Clear method. Then it will add all the all members provided in the vector v
      Parameters:
      v - List containing all the members this membership will contain

    • set

      public Membership set(Membership m)
      Clears the membership and adds all members of a given membership parameter. Prior to setting membership this method will clear out all the old members of this membership by invoking the clear method.
      Parameters:
      m - a membership containing all the members this membership will contain

    • merge

      public Membership merge(Collection<Address> new_mems, Collection<Address> suspects)
      Merges membership with the new members and removes suspects. The Merge method will remove all the suspects and add in the new members. It will do it in the order 1. Remove suspects 2. Add new members the order is very important to notice.
      Parameters:
      new_mems - - a vector containing a list of members (Address) to be added to this membership
      suspects - - a vector containing a list of members (Address) to be removed from this membership

    • contains

      public boolean contains(Address member)
      Returns true if the provided member belongs to this membership
      Parameters:
      member -
      Returns:
      true if the member belongs to this membership

    • sort

      public Membership sort()

    • copy

      public Membership copy()
      Returns a copy of this membership
      Returns:
      an exact copy of this membership

    • size

      public int size()
      Returns the number of addresses in this membership

    • isEmpty

      public boolean isEmpty()

    • elementAt

      public Address elementAt(int index)
      Returns the component at the specified index
      Parameters:
      index - 0..size()-1
      Throws:
      ArrayIndexOutOfBoundsException - If the index is negative or not less than the current size of this object

    • getFirst

      public Address getFirst()

    • isCoord

      public boolean isCoord(Address mbr)

    • nextCoord

      public Address nextCoord()

    • getPrevious

      public Address getPrevious(Address mbr)
      Returns the members to the left of mbr
      Parameters:
      mbr - The member whose neighbor to the left should be returned
      Returns:
      The neighbor to the left, or null if mbr is null, or the size is less than 2.

    • getNext

      public Address getNext(Address mbr)
      Returns the members next to mbr.
      Parameters:
      mbr - The member whose neighbor to the right should be returned
      Returns:
      The neighbor to the right, or null if mbr is null, or the size is less than 2.

    • toString

      public String toString()
      Overrides:
      toString in class Object