Solved Problem trying to change another player's gamemode

I'm trying to make a plugin that when you type /gmc <player> it changes the gamemode of the player targetted. But when I do it there are a few bugs. For example, when someone is in adventure mode then I change it to creative and then try to change their gamemode back to adventure, it tells me they are in adventure. New to bukkit btw.

Here's my code :

Code:

package commands;

import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.GameMode;
import org.bukkit.command.Command;
import org.bukkit.command.CommandExecutor;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import org.bukkit.event.Listener;

import net.minecraft.server.v1_8_R3.CommandExecute;

public class Gamemodes extends CommandExecute implements Listener, CommandExecutor {

    public String prefix = (ChatColor.BLUE + "Stone" + ChatColor.GRAY + "brick" + ChatColor.GOLD + ">>");

    public String cmd1 = "gmc";
    public String cmd2 = "gms";
    public String cmd3 = "gma";
    public String cmd4 = "gmsp";

    @Override

    public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {
        if (sender instanceof Player) {

            Player player = (Player) sender;
            if (sender.hasPermission("change.gamemode")) {
                if (cmd.getName().equalsIgnoreCase(cmd1)) {
                    if (args.length != 0) {
                        if (((Player) player).getGameMode() != GameMode.CREATIVE) {
                        Player target = (Player) Bukkit.getPlayer(args[0]);
                        ((Player) target).setGameMode(GameMode.CREATIVE);
                        player.sendMessage(prefix + ChatColor.GREEN + " Changed " + ChatColor.WHITE + target.getName() + ChatColor.GREEN +  "'s gamemode to creative");
                        return true;
                    }else {
                        player.sendMessage(prefix + ChatColor.RED + " This player is already in creative mode");
                        return true;
                    }
                    } else {
                        if (((Player) player).getGameMode() != GameMode.CREATIVE) {
                            ((Player) player).setGameMode(GameMode.CREATIVE);
                            player.sendMessage(prefix + ChatColor.GREEN + " Changed your gamemode to creative");
                            return true;
                        } else {
                            player.sendMessage(prefix + ChatColor.RED + " You already are in creative mode");
                            return true;
                        }

                    }
                }

                if (cmd.getName().equalsIgnoreCase(cmd2)) {
                    if (args.length != 0) {
                        if (((Player) player).getGameMode() != GameMode.SURVIVAL) {
                        Player target = (Player) Bukkit.getPlayer(args[0]);
                        ((Player) target).setGameMode(GameMode.SURVIVAL);
                        player.sendMessage(prefix + ChatColor.GREEN + " Changed " + ChatColor.WHITE + target.getName() + ChatColor.GREEN +  "'s gamemode to survival");
                        return true;
                    }else {
                        player.sendMessage(prefix + ChatColor.RED + " This player is already in survival mode");
                        return true;
                    }
                    } else {
                        if (((Player) player).getGameMode() != GameMode.SURVIVAL) {
                            ((Player) player).setGameMode(GameMode.SURVIVAL);
                            player.sendMessage(prefix + ChatColor.GREEN + " Changed your gamemode to survival");
                            return true;
                        } else {
                            player.sendMessage(prefix + ChatColor.RED + " You already are in survival mode");
                            return true;
                        }

                    }
                }

                if (cmd.getName().equalsIgnoreCase(cmd3)) {
                    if (args.length != 0) {
                        if (((Player) player).getGameMode() != GameMode.ADVENTURE) {
                        Player target = (Player) Bukkit.getPlayer(args[0]);
                        ((Player) target).setGameMode(GameMode.ADVENTURE);
                        player.sendMessage(prefix + ChatColor.GREEN + " Changed " + ChatColor.WHITE + target.getName() + ChatColor.GREEN +  "'s gamemode to adventure");
                        return true;
                    }else {
                        player.sendMessage(prefix + ChatColor.RED + " This player is already in adventure mode");
                        return true;
                    }
                    } else {
                        if (((Player) player).getGameMode() != GameMode.ADVENTURE) {
                            ((Player) player).setGameMode(GameMode.ADVENTURE);
                            player.sendMessage(prefix + ChatColor.GREEN + " Changed your gamemode to adventure");
                            return true;
                        } else {
                            player.sendMessage(prefix + ChatColor.RED + " You already are in adventure mode");
                            return true;
                        }

                    }
                }
                if(cmd.getName().equalsIgnoreCase(cmd4)) {
                    if(args.length != 0) {
                        Player target = (Player) Bukkit.getPlayer(args[0]);
                        if(target.getGameMode() != GameMode.SPECTATOR) {
                            target.setGameMode(GameMode.SPECTATOR);
                            player.sendMessage(prefix + ChatColor.GREEN + " Changed " + target.getName() + " to spectator mode");
                            return true;
                        }else {
                            player.sendMessage(prefix + ChatColor.RED + " This player is already in spectator mode");
                            return true;
                        }
                    }else {
                        if(player.getGameMode() != GameMode.SPECTATOR) {
                            player.sendMessage(prefix + ChatColor.GREEN + " Change your gamemode to spectator");
                            player.setGameMode(GameMode.SPECTATOR);
                            return true;
                        }else {
                            player.sendMessage(prefix + ChatColor.RED + " You already are in spectator mode");
                            return true;
                        }
                    }
                }
            } else {
                sender.sendMessage(prefix + ChatColor.RED + " You do not have the permission to perform this command");
                return true;
            }

        } else {
            sender.sendMessage("You are not a player");
            return true;
        }
        return false;
    }

}

 

@Warpaka A few things:

• Your class extends CommandExecute and implements Listener, you can remove both of those. You just need to implement CommandExecutor for command registration.
  
• You are unnecessarily casting Player to Player several times.
• You can use guard clauses to reduce the amount of nested if and else statements.
• You should indent your code once when entering a scope and remove an indent when exiting a scope. This is for readability.
  
• You should check for possible null values (e.g. The returned value for #getPlayer(String) might be null).
• Try debugging (print messages to the console), that might give you an explanation as to why your method is not working as intended.

 

Thanks ! Fixed (Too many returns and null)

 

That's cool, I wasn't aware there was a term for that