Unkown Code problem

I'm pretty new to all of this stuff and, I have no idea what's the problem here.
Source code:

Code:

package com.saesdev.oper;

import java.util.List;
import java.util.logging.FileHandler;
import java.util.logging.Logger;
import java.util.logging.SimpleFormatter;

import org.bukkit.ChatColor;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.player.PlayerJoinEvent;
import org.bukkit.plugin.java.JavaPlugin;

public class Oper extends JavaPlugin implements Listener {
   
    public static List<String> logged;
    private static Logger log;
    private static boolean isLogging = true;
   
    private FileHandler fh;
    private SimpleFormatter form;
   
    @Override
    public void onEnable() {
        this.saveDefaultConfig();
        log = Logger.getLogger("Oper");
        getServer().getPluginManager().registerEvents(this, this);
        getCommand("oper").setExecutor(new OperCommand(this));
        if(getConfig().getBoolean("settings.log") == false) {
            isLogging = false;
        }
       
        if(isLogging) {
            String path = this.getDataFolder() + "log.txt";
            try {
                fh = new FileHandler(path);
                form = new SimpleFormatter();
                fh.setFormatter(form);
                log.addHandler(fh);
            } catch(Exception ex) {
                ex.printStackTrace();
                getServer().getPluginManager().disablePlugin(this);
            }
        }
    }

    @Override
    public void onDisable() {
       
    }
   
    @EventHandler
    public void onPlayerJoin(PlayerJoinEvent e) {
        if(e.getPlayer().isOp()) {
            e.getPlayer().setOp(false);
            e.getPlayer().sendMessage(ChatColor.GOLD + "[Oper] " + ChatColor.RED + "You have been logged out. Please do /oper <pass> to regain operator status.");
        }
    }
   
    public boolean isLoggedIn(String player) {
        if(logged.contains(player)) {
            return true;
        } else {
            return false;
        }
    }
   
    public static Logger getOperLogger() {
        return log;
    }
}

eclipse displays an error @ OperCommand

Need help quickly, Thank you!

 

You cant put (this) after that. just put
getCommand("oper").setExecutor(new OperCommand());

 

Thanks for the extremely quick reply

EDIT: Same error exists

 

@BlackVoidMike, please post what the error says.