PlayerInteractEvent

How to close mistake:

Code:

Caused by: java.lang.NullPointerException
        at me.xcraftrayx.pl.Button.buttonClick(Button.java:34)

This mistake show me when I clicked block and is cancel this event.

My code:

Code:

package me.xcraftrayx.pl;

import java.util.HashMap;

import javax.persistence.GenerationType;

import org.bukkit.Bukkit;
import org.bukkit.Location;
import org.bukkit.Material;
import org.bukkit.World;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.player.PlayerInteractEvent;
import org.bukkit.plugin.java.JavaPlugin;

public class Button extends JavaPlugin implements Listener {
   
    public void onEnable()
    {
        Bukkit.getPluginManager().registerEvents(this, this);
    }
    HashMap<Player, Integer> Mapa = new HashMap<>();
   
    Location Loc1 = new Location(Bukkit.getWorld("world2"), 46, 53, -3);
    Location Loc2 = new Location(Bukkit.getWorld("world2"), 44, 55, 15);
    Location Loc3 = new Location(Bukkit.getWorld("world2"), 39, 54, 16);
    Location Loc4 = new Location(Bukkit.getWorld("world2"), 37, 56, 2);
    Location Loc5 = new Location(Bukkit.getWorld("world2"), 41, 55, -1);
   
    @EventHandler
    public void buttonClick(PlayerInteractEvent e)
    {
        if(e.getClickedBlock().getType() == Material.STONE_BUTTON)
        {
            double x = e.getClickedBlock().getLocation().getX();
            double y = e.getClickedBlock().getLocation().getY();
            double z = e.getClickedBlock().getLocation().getZ();
       
            Location loc = new Location(Bukkit.getWorld("world2"), x, y, z);
            Player p = e.getPlayer();
                if(loc.equals(Loc1))
                {
                    Mapa.put(p, 1);
                    p.sendMessage("To jest 1 guzik");
                    System.out.println(Mapa.get(p));
                }
       
                if(loc.equals(Loc2))
                {
                    if(Mapa.containsKey(p))
                    {
                        if(Mapa.get(p).equals(1))
                        {
                            Mapa.put(p, 2);
                            p.sendMessage("To jest 2 guzik");
                            System.out.println(Mapa.get(p));
                        }
                        else{
                            Mapa.remove(p);
                        }
                    }
                }
       
                if(loc.equals(Loc3))
                {
                    if(Mapa.containsKey(p))
                    {
                        if(Mapa.get(p).equals(2))
                        {
                            Mapa.put(p, 3);
                            p.sendMessage("To jest 3 guzik");
                            System.out.println(Mapa.get(p));
                        }
                        else{
                            Mapa.remove(p);
                        }
                    }
                }
       
                if(loc.equals(Loc4))
                {
                    if(Mapa.containsKey(p))
                    {
                        if(Mapa.get(p).equals(3))
                        {
                            Mapa.remove(p);
                            p.sendMessage("To jest 4 guzik");
                            p.sendMessage("Zostaniesz wynagrodzony!");
                        }
                        else{
                            Mapa.remove(p);
                        }
                    }
                }
        }
    }

}

 

Basically, NullPointerException means one of your values has returned null. In this instance, it should say something like (Java:##) to show the exact line with the error. This is how you bug-fix NullPointerException. Anyway, here you have attempted to identify a block type with a Material. This is an error because Material is not Block.

Line 34, the if statement

 

As Harieo said, check that if statement. Use .equals to compare objects instead of "==".

 

@Ligachamp When i ussed "==" problem don't close...
@Harieo This mistake pops me when I hold item in hand and clicked block under me, so when I haven't item in hand no mistake... how to solve it?

 

== is fine on Enum's

@CraftRay It causes the NPE because you're interacting with the item in hand, not the block,(I'm guessing) check if they clicked a block first before going through with everything else

 

I believe it is an eventhandler... So I don't see why you have discounted my answer?
It may also be that when you place a block, the interact suddenly changes?

Try making sure iteminhand is nothing as a safeguard

 

Oh, you're right. Didn't think of that ^^"

Isn't the metod to get the actual material ".getMaterial()" instead of ".getType()"?

After all, what about "world2"? Does it even exist?

 

getType() is correct

 

@mcdorli Thanks
It was solved!

 

@CraftRay
It you who has to mark this thread as solveD:

Go to the top of this page> look for a "thread tools" button, click edit title, and add the solved prefix.