Adding money to a player's account with Bukkit Vault API

Question

I am working on a plugin for my server for the KitPvP section.

Right now I am adding MoneyPerKill but have run into a problem.

My code is:

package com.lobbyist.junk.kitpvp;

import net.milkbowl.vault.economy.Economy;
import net.milkbowl.vault.economy.EconomyResponse;

import org.bukkit.ChatColor;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.entity.EntityDeathEvent;
import org.bukkit.event.entity.PlayerDeathEvent;
import org.bukkit.plugin.RegisteredServiceProvider;

public class MoneyPerKill implements Listener {

    public static Economy econ = null;

    @EventHandler
    public void onPlayerDeathEvent(PlayerDeathEvent event) {
        Player player = event.getEntity();
        Player killer = player.getKiller();
        EconomyResponse r = econ.depositPlayer(killer, 10.00);
        if (r.transactionSuccess()) {
            killer.sendMessage(ChatColor.GOLD + "You recieved $10 for killing" +  player.getDisplayName());
        }
    }
}

In my main class Main.java I also registered the events.

And in Main.java I have:

public static Economy econ = null;
private boolean setupEconomy() {
    RegisteredServiceProvider<Economy> economyProvider = getServer().getServicesManager().getRegistration(net.milkbowl.vault.economy.Economy.class);
    if (economyProvider != null) {
        econ = economyProvider.getProvider();
    }

    return (econ != null);
}

The problem is that it doesn't give the killer money when they kill a player.

Answer 1

From what I can see, you're registering and referencing the Economy service object in Main.java's econ field, but in your MoneyPerKill.java PlayerDeathEvent listener, you're referencing econ as in MoneyPerKill's econ, which is null. So at this point in time, your code will throw NullPointerExceptions whenever a player dies.

To fix the issue, you need to reference Main.java's econ field. To do that, you type Main.econ.depositPlayer(killer, 10.00).

P.S. You should consider using your Main class instance instead of making static fields all over the place, but that's off topic.

Also consider what Rishaan Gupta said.