PlayerItemConsumeEvent Error

Hello, I made some plugin for my server. but My plugin have error
-Source-

Code:java

package lego;
 
import com.herocraftonline.heroes.Heroes;
import com.herocraftonline.heroes.characters.CharacterManager;
import com.herocraftonline.heroes.characters.Hero;
import com.herocraftonline.heroes.characters.classes.HeroClass;
import com.herocraftonline.heroes.characters.classes.HeroClassManager;
import java.io.IOException;
 
import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.Material;
 
import org.bukkit.configuration.file.FileConfiguration;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.block.Action;
import org.bukkit.event.player.PlayerInteractEvent;
import org.bukkit.event.player.PlayerItemConsumeEvent;
import org.bukkit.event.player.PlayerJoinEvent;
import org.bukkit.event.player.PlayerMoveEvent;
import org.bukkit.plugin.PluginManager;
import org.bukkit.plugin.RegisteredServiceProvider;
import org.bukkit.plugin.java.JavaPlugin;
 
public class legopotion extends JavaPlugin implements Listener {
 
private static CharacterManager heroes;
private static HeroClassManager heroes1;
 
//Startup
 
public void onEnable(){
 
PluginManager PluginM = getServer().getPluginManager();
Bukkit.getServer().getPluginManager().registerEvents(this, this);
 
//I'm starting the engine! Vroom! Vroom!
if(this.getServer().getPluginManager().getPlugin("Heroes") != null){
heroes = ((Heroes)PluginM.getPlugin("Heroes")).getCharacterManager();
log(0,"히어로즈 발견");
}else{
log(0,"[ConfigurableMessages] Heroes not found");
}
 
 
 
 
log(0, "Enabled!");
}
 
 
 
public void onDisable(){
log(0, "Disabled!");
}
 
/*
* Vault
* -----
*/
 
 
 
/*
* -----
*/
 
public void log(int level, String out){
if(level == 0) getLogger().info(out);
if(level == 1) getLogger().warning(out);
if(level == 2) getLogger().severe(out);
}
 
 
public static CharacterManager getHeroes() {
return heroes;
}
 
public static HeroClassManager getHeroes1() {
return heroes1;
}
 
public void addMana(Player player)
{
Hero hero = getHeroes().getHero(player);
int mana = 30;
if (hero.getMana() + mana > hero.getMaxMana()) {
hero.setMana(hero.getMaxMana());
} else {
hero.setMana(hero.getMana() + mana);
}
player.sendMessage(ChatColor.AQUA + "You regained " + ChatColor.DARK_AQUA + mana + ChatColor.AQUA + " mana");
if (player.getItemInHand() != null) {
if (player.getItemInHand().getAmount() == 1)
{
player.setItemInHand(null);
player.updateInventory();
}
else
{
player.getItemInHand().setAmount(player.getItemInHand().getAmount() - 1);
}
}
}
 
@EventHandler
public void onPlayerInteract(PlayerItemConsumeEvent event)
{
short potionID = event.getItem().getDurability();
if (potionID == 0) {
addMana(event.getPlayer());
 
}
 
}
}

-server.log-

Code:

2014-01-24 00:58:52 [SEVERE] Could not pass event PlayerItemConsumeEvent to Legopotion v1.0
org.bukkit.event.EventException
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:437)
    at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62)
    at org.bukkit.plugin.TimedRegisteredListener.callEvent(TimedRegisteredListener.java:31)
    at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:479)
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:464)
    at net.minecraft.entity.player.EntityPlayer.func_71036_o(EntityPlayer.java:499)
    at net.minecraft.entity.player.EntityPlayerMP.func_71036_o(EntityPlayerMP.java:1237)
    at net.minecraft.entity.player.EntityPlayer.func_70071_h_(EntityPlayer.java:325)
    at net.minecraft.entity.player.EntityPlayerMP.func_71127_g(EntityPlayerMP.java:424)
    at net.minecraft.network.NetServerHandler.func_72498_a(NetServerHandler.java:509)
    at net.minecraft.network.packet.Packet10Flying.func_73279_a(Packet10Flying.java:51)
    at net.minecraft.network.TcpConnection.func_74428_b(TcpConnection.java:470)
    at net.minecraft.network.NetServerHandler.func_72570_d(NetServerHandler.java:233)
    at net.minecraft.network.NetworkListenThread.func_71747_b(NetworkListenThread.java:54)
    at net.minecraft.server.dedicated.DedicatedServerListenThread.func_71747_b(DedicatedServerListenThread.java:34)
    at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:914)
    at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:330)
    at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:781)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:663)
    at net.minecraft.server.ThreadMinecraftServer.run(ThreadMinecraftServer.java:16)
Caused by: java.lang.NullPointerException
    at lego.legopotion.addMana(legopotion.java:87)
    at lego.legopotion.onPlayerInteract(legopotion.java:113)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:435)
    ... 19 more

English is my second language, so please excuse any English mistakes.
Thanks

 

Code:

Caused by: java.lang.NullPointerException
    at lego.legopotion.addMana(legopotion.java:87)
    at lego.legopotion.onPlayerInteract(legopotion.java:113)

Check line 87 in your addMana() method.

Code:java

Hero hero = getHeroes().getHero(player);

Perhaps the hero is null?