Treefeller like behaviour for Bukkit listener

  // You may want to specify the priority for this listener
  @EventHandler
  public void onblockBreak(BlockBreakEvent event) {
    if (!event.isCancelled()) {
      Block brokenBlock = event.getBlock();
       if (brokenBlock.getType() == Material.LOG || brokenBlock.getType() == Material.LOG_2) {
        breakAboveLogs(brokenBlock);
      }
    }
  }

  private void breakAboveLogs(Block block) {
    Location loc = block.getLocation();
    loc.add(0, 1, 0);
    Block aboveBlock = block.getWorld().getBlockAt(loc);
    if (aboveBlock.getType() == Material.LOG || aboveBlock.getType() == Material.LOG_2) {
      aboveBlock.breakNaturally();
      breakAboveLogs(aboveBlock);
    }
  }