public class MyListener extends PluginListener {
    public boolean onCommand(Player player, String[] split) {
        player.sendMessage("You used a command.");
        if (split[0].equals("/forcedestroy") && player.canUseCommand("/forcedestroy")) {
            player.sendMessage("You used the forcedestroy command.");
            Location L = player.getLocation();
            player.sendMessage("I have your location...");
            Block underPlayer = etc.getServer().getBlockAt((int) L.x, (int) L.y-1, (int) L.z);
            underPlayer.setType(0);
            player.sendMessage("And now a block near you should vanished into thin air!");
            return true;
        }
        else{
            return false;
        }
    }
}