private void checkJoinRoomPreconditionIsOutcast(@Nonnull final JID realAddress, @Nonnull final Affiliation affiliation ) throws ForbiddenException
    {
        boolean canJoin = affiliation != Affiliation.outcast;

        Log.trace( "{} Room join precondition 'is outcast': User '{}' {} join room '{}'.", canJoin ? "PASS" : "FAIL", realAddress, canJoin ? "can" : "cannot", this.getJID() );
        if (!canJoin) {
            throw new ForbiddenException( "You have been banned (marked as 'outcast') from this room." );
        }
    }
Checks if the person that attempts to join has been banned from the room.

@param realAddress The address of the user that attempts to join.
@throws ForbiddenException when joining is prevented by virtue of the user being banned.
xmppserver/src/main/java/org/jivesoftware/openfire/muc/MUCRoom.java