Development Assistance Teleport Command is not working

Hello my Tp Command is not working i tryed it ingame no error in Console its one of my first commands.

Code:

public class Tp implements CommandExecutor {
    private Main plugin;

    public Tp(Main plugin) {
           this.plugin = plugin;
    }

    @Override
    public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {
           Player p = (Player) sender;
           String playerName = p.getName();
           if(p.hasPermission("phai.tp")) {
               if(args.length == 0 ) {
                  p.sendMessage(Main.prefix + "§6/Tp <Spieler> zu <Spieler>");
               } else if(args.length == 1) {
                   Player targetPlayer = Bukkit.getServer().getPlayer(args[0]);
                   String targetName = targetPlayer.getName();
                  Location t1 = targetPlayer.getLocation();
                   p.teleport(t1);
                   p.sendMessage(Main.prefix + "Du wurdest zu" + targetName + " teleportiert.");
               }
           } else {
               p.sendMessage(Main.prefix + "§cKeine Rechte!");
                  p.playSound(p.getLocation(), org.bukkit.Sound.ANVIL_LAND, 1.0F, 1.0F);
           }
          
  
           
                  
               if(args.length == 2) {
                  
                   Player von = Bukkit.getServer().getPlayer(args[0]);
                   String fn = von.getName();
                   Player zu = Bukkit.getServer().getPlayer(args[1]);
                   String tn = zu.getName();
                   Location t1 = zu.getLocation();
                   von.teleport(t1);
                   von.sendMessage(Main.prefix + "§4Du wurdest teleportiert");
                   zu.sendMessage(Main.prefix + "§4Du wurdest teleportiert");
               } else if(args.length >2) {
                   p.sendMessage(Main.prefix + "§cZu viele Argumente");
               }
      
              
        return false;
    }
}

please help me.

 

@Phai_

1. Have you registered the executor?
2. Don't blindly cast sender to a player. Consoles and command blocks can send commands, so you need to check if the sender is a player before you cast it.
3. targetPlayer can be null if the player is not online/ does not exist. Null check targetplayer before you get their name.
4. The last if statement, for args length == 2, you do not check for the player's permission. You may want to move this into the args length check above.