Example Boundary Wrapper

/*
Sample boundary teleporter
Written in about 5 minutes by cembry90
May contain imperfections; just a demonstration

        compass
        N (-Z)
W (-X)          E (+X)
        S (+Z)
*/

public class BoundaryListener implements Listener {
    int minX = -1000, maxX = 1000,
        minZ = -1000, maxZ = 1000;

    @EventHandler(priority = EventPriority.NORMAL)
    public void onPlayerMove(PlayerMoveEvent e) {
        Player p = e.getPlayer();
        Location loc = p.getLocation();
        World world = p.getWorld();
        int curX = loc.getBlockX(),
            curY = loc.getBlockY(),
            curZ = loc.getBlockZ();

        if (curX < minX) {
            p.teleport(new Location(world, maxX, curY, curZ));
        } else if (curX > maxX) {
            p.teleport(new Location(world, minX, curY, curZ));
        } else if (curZ < minZ) {
            p.teleport(new Location(world, curX, curY, maxZ));
        } else if (curZ > maxZ) {
            p.teleport(new Location(world, curX, curY, minZ));
        }
    }
}