spread
Class MembershipInfo

java.lang.Object
  |
  +--spread.MembershipInfo

public class MembershipInfo

extends java.lang.Object

A MembershipInfo object represents information stored in a membership message. To check if a message is a membership message, use SpreadMessage.isMembership():

 if(message.isMembership() == true)
     System.out.println("Membership message.");
 

To get the MembershipInfo object from a membership message, use SpreadMessage.getMembershipInfo():

 MembershipInfo membershipInfo = message.getMembershipInfo();
 

A MembershipInfo object can be used to get information on what caused the membership change (the is*() methods) and extra information about the change (the get*() methods). Which get*() methods are valid for a particular membership message depends on what caused the message.

Method Summary

SpreadGroup	getDisconnected() Gets the private group of the member who disconnected.
SpreadGroup	getGroup() Gets a SpreadGroup object representing the group that caused this message.
GroupID	getGroupID() Gets the GroupID for this group membership at this point in time.
SpreadGroup	getJoined() Gets the private group of the member who joined.
SpreadGroup	getLeft() Gets the private group of the member who left.
SpreadGroup[]	getMembers() Gets the private groups for all the members in the new group membership.
SpreadGroup[]	getStayed() Gets the private groups of the members who were not partitioned.
boolean	isCausedByDisconnect() Check if this message was caused by a disconnect.
boolean	isCausedByJoin() Check if this message was caused by a join.
boolean	isCausedByLeave() Check if this message was caused by a leave.
boolean	isCausedByNetwork() Check if this message was caused by a network partition.
boolean	isRegularMembership() Check if this is a regular membership message.
boolean	isSelfLeave() Check if this is a self-leave message.
boolean	isTransition() Check if this is a transition message.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

isRegularMembership

public boolean isRegularMembership()

Check if this is a regular membership message. If true, getGroup(), getGroupID(), and getMembers() are valid. One of getJoined(), getLeft(), getDisconnected(), or getStayed() are valid depending on the type of message.

Returns:

true if this is a regular membership message

See Also:

getGroup(), getGroupID(), getMembers(), getJoined(), getLeft(), getDisconnected(), getStayed()

isTransition

public boolean isTransition()

Check if this is a transition message. If true, getGroup() is the only valid get*() function.

Returns:

true if this is a transition message

See Also:

getGroup()

isCausedByJoin

public boolean isCausedByJoin()

Check if this message was caused by a join. If true, getJoined() can be used to get the group member who joined.

Returns:

true if this message was caused by a join

See Also:

getJoined()

isCausedByLeave

public boolean isCausedByLeave()

Check if this message was caused by a leave. If true, getLeft() can be used to get the group member who left.

Returns:

true if this message was caused by a leave

See Also:

getLeft()

isCausedByDisconnect

public boolean isCausedByDisconnect()

Check if this message was caused by a disconnect. If true, getDisconnected() can be used to get the group member who left.

Returns:

true if this message was caused by a disconnect

See Also:

getDisconnected()

isCausedByNetwork

public boolean isCausedByNetwork()

Check if this message was caused by a network partition. If true, getStayed() can be used to get the members who are still in the group.

Returns:

true if this message was caused by a network partition

See Also:

getStayed()

isSelfLeave

public boolean isSelfLeave()

Check if this is a self-leave message. If true, getGroup() is the only valid get*() function.

Returns:

true if this is a self-leave message

See Also:

getGroup()

getGroup

public SpreadGroup getGroup()

Gets a SpreadGroup object representing the group that caused this message.

Returns:

the group that caused this message

getGroupID

public GroupID getGroupID()

Gets the GroupID for this group membership at this point in time. This is only valid if isRegularMembership() is true. If it is not true, null is returned.

Returns:

the GroupID for this group memebership at this point in time

getMembers

public SpreadGroup[] getMembers()

Gets the private groups for all the members in the new group membership. This list will be in the same order everywhere it is received. This is only valid if isRegularMembership() is true. If it is not true, null is returned.

Returns:

the private groups for everyone in the new group membership

getJoined

public SpreadGroup getJoined()

Gets the private group of the member who joined. This is only valid if both isRegularMembership() and isCausedByJoin() are true. If either or both are false, null is returned.

Returns:

the private group of the member who joined

See Also:

isCausedByJoin()

getLeft

public SpreadGroup getLeft()

Gets the private group of the member who left. This is only valid if both isRegularMembership() and isCausedByLeave() are true. If either or both are false, null is returned.

Returns:

the private group of the member who left

See Also:

isCausedByLeave()

getDisconnected

public SpreadGroup getDisconnected()

Gets the private group of the member who disconnected. This is only valid if both isRegularMembership() and isCausedByDisconnect() are true. If either or both are false, null is returned.

Returns:

the private group of the member who disconnected

See Also:

isCausedByDisconnect()

getStayed

public SpreadGroup[] getStayed()

Gets the private groups of the members who were not partitioned. This is only valid if both isRegularMembership() and isCausedByNetwork() are true. If either or both are false, null is returned.

Returns:

the private groups of the members who were not partitioned

See Also:

isCausedByNetwork()