gistfile1.txt

import org.bukkit.command.Command;
import org.bukkit.command.CommandExecutor;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;

import java.util.HashSet;
import java.util.Set;

class CommandTest implements CommandExecutor {
    private final Set<Subcommand> subcommands = new HashSet<>();
    {
        subcommands.add(new SuicideCommand());
        subcommands.add(new EchoCommand());
    }

    @Override
    public boolean onCommand(CommandSender commandSender, Command command, String label, String[] args) {
        for(Subcommand sub : subcommands) {
            if(sub.getLabel().equalsIgnoreCase(args[0])) {
                return sub.onCommand(commandSender, args);
            }
        }
        // If no subcommands could handle this.
        commandSender.sendMessage("Invalid subcommand");
        return false;
    }
}

/**
* Template for a subcommand
*/
abstract class Subcommand {
    private final String label;

    /**
     * Should be called by subclass with the appropriate label
     * @param label Label of the subcommand
     */
    public Subcommand(String label) {
        this.label = label;
    }

    /**
     * Gets the label of the subcommand
     * @return The label of the subcommand.
     */
    public final String getLabel() {
        return this.label;
    }

    /**
     * Execute a subcommand if the name matches the first argument of the main command.
     * @param commandSender The sender of the command.
     * @param args Arguments, starting with the label of the subcommand
     * @return true if the command was processed successfully.
     */
    public abstract boolean onCommand(CommandSender commandSender, String[] args);
}

/**
* SuicideCommand can only be excecuted by a player, who will recieve a message
*/
final class SuicideCommand extends Subcommand {
    public SuicideCommand() {
        super("suicide");
    }

    @Override
    public boolean onCommand(CommandSender commandSender, String[] args) {
        if(commandSender instanceof Player) {
            commandSender.sendMessage("Killing you");
            ((Player) commandSender).setHealth(0D);
            // Command handled
            return true;
        }

        // Not a player ;(
        return false;
    }
}

/**
* EchoCommand can only be executed by the console, who will have the args repeated to them
*/
final class EchoCommand extends Subcommand {
    public EchoCommand() {
        super("kickall");
    }

    @Override
    public boolean onCommand(CommandSender commandSender, String[] args) {
        if(commandSender instanceof Player) {
            commandSender.sendMessage("Can only be sent by console");
            // Not console
            return false;
        }

        StringBuilder toEcho = new StringBuilder();
        for(String string : args) {
            toEcho.append(string).append(' ');
        }

        commandSender.sendMessage(toEcho.toString());

        return true;
    }
}