Simple Command

• Related: Command, KapiPlugin, @SubCommand

For this example, we will be recreating a simple version of the /give command. Players will be able to use /mygive <material> <amount>.

Extending Command

Create a new class that extends Command like so:

import io.github.kapimc.kapi.commands.Command;

public class MyGiveCommand extends Command {

}

tip

Make sure you are using the Command class from Kapi and not the one from Bukkit/Spigot

Registering the Command

Before we forget, let's register it now.
You'll also need to register it in the plugin.yml file like any other command.

Add the registerCommand() method to onPluginLoad() inside your main plugin class

public class YourMainPluginClass extends KapiPlugin {
    @Override
    public void onPluginLoad() {
        registerCommand("mygive", new MyGiveCommand());
    }
}

Adding a SubCommand

Let's make our command finally do something.

public class MyGiveCommand extends Command {
    @SubCommand
    public void give(CommandSender sender, Material item, int amount) {
        if (sender instanceof Player player) {
            ItemStack itemStack = new ItemStack(item, amount);
            player.getInventory().addItem(itemStack);
        } else {
            String error = "Only players can use this command!";
            // Equivalent to sender.sendMessage(ChatColor.RED + error);
            Log.error(error, sender);
        }
    }
}

That's it, compile your plugin and go test it!

For a method to be considered valid, it must:

• Be annotated with @SubCommand
• Be public but not static
• Return void
• Have CommandSender or any subclass of it as the first parameter

Our example works, but here's another way of achieving it, instead of checking if sender is a player, we can directly use Player.

public class MyGiveCommand extends Command {
    @SubCommand
    public void give(Player player, Material item, int amount) {
        ItemStack itemStack = new ItemStack(item, amount);
        player.getInventory().addItem(itemStack);
    }
}

The only disadvantage with this approach is that you won't be able to provide your own custom error message, so choose which one you prefer.

All built-in types

You can only use certain types as parameters to @SubCommand methods, here's a list of all the built-in types.

tip

You can register your own types, see Making your own argument parser.

Primitives

• String
• boolean / Boolean
• short / Short
• int / Integer
• long / Long
• float / Float
• double / Double
• Any enum

Collections

• Arrays of any type
• List<T>

Kapi

• Option - for optional arguments

Minecraft

• Material
• Location
• Player