A View (JavaGroups.View) is a local representation of the current membership of a group. Only one view is installed in a channel at a time. Views contain the address of its creator, an ID and a list of member addresses. Views are generated by a previously elected coordinator and are installed in each channel belonging to the same group whenever a member joins or leaves. Each view is uniquely identified by the creator/ID pair, and the ID is incremented for each new view. All members of a group see the same sequence of views.
Note that there is a comparison function which orders all the members of a group in the same way. Usually, the first member of the list if the coordinator (the one who emits new views). Thus, whenever the membership changes, every member can determine the coordinator easily and without having to contact other members.