NullPointerException

I am having a problem getting the block below the ItemFrame, can someone please see what I'm doing wrong?

Code:

package com.kassestral.plugins.imperium.events;

import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.Location;
import org.bukkit.Material;
import org.bukkit.block.Block;
import org.bukkit.block.Sign;
import org.bukkit.entity.Entity;
import org.bukkit.entity.ItemFrame;
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.PlayerInteractEntityEvent;
import org.bukkit.event.player.PlayerInteractEvent;
import org.bukkit.inventory.Inventory;
import org.bukkit.inventory.ItemStack;

public class ShopHandler implements Listener {
   
    @EventHandler
    public void createShop(PlayerInteractEntityEvent event){
        Player player = event.getPlayer();
        Entity entityClicked = event.getRightClicked();
        
        if(entityClicked instanceof ItemFrame){
            ItemFrame itemframe = (ItemFrame) entityClicked;
           
            if(player.isOp()) {
                itemframe.setItem(player.getItemInHand());
                setSign(itemframe.getLocation(), itemframe.getItem().getType().toString());
            }
        }
    }
   
    @SuppressWarnings("deprecation")
    @EventHandler
    public void openShop(PlayerInteractEvent event){
        Player player = event.getPlayer();
       
        if(event.getAction().equals(Action.RIGHT_CLICK_BLOCK)) {
            Sign sign = (Sign) event.getClickedBlock();
           
            if(getSignType(sign.getLocation()) != "none") {
                Inventory inventory = Bukkit.createInventory(null, 9, ChatColor.WHITE + "Shop");
                ItemStack placefiller = new ItemStack(160, 1);
                ItemStack buying = getItemFrameItem(sign.getLocation());
                ItemStack selling = getItemFrameItem(sign.getLocation());
               
                placefiller.getItemMeta().setDisplayName("");
                buying.getItemMeta().setDisplayName(ChatColor.WHITE + "Buying");
                selling.getItemMeta().setDisplayName(ChatColor.WHITE + "Selling");
               
                inventory.setItem(0, placefiller);
                inventory.setItem(1, placefiller);
                inventory.setItem(2, placefiller);
                inventory.setItem(3, buying);
                inventory.setItem(4, placefiller);
                inventory.setItem(5, selling);
                inventory.setItem(6, placefiller);
                inventory.setItem(7, placefiller);
                inventory.setItem(8, placefiller);
               
                player.openInventory(inventory);
            }
        }
    }
   
    private String getSignType(Location location) {
       
        if(location.getBlock().getState() instanceof Sign) {
            Sign shop_sign = (Sign) location.getBlock().getState();
           
            if(shop_sign.getLine(1).equalsIgnoreCase(ChatColor.WHITE + "Buy")) {
                return "buy";
            }
            else if(shop_sign.getLine(1).equalsIgnoreCase(ChatColor.WHITE + "Sell")) {
                return "sell";
            }
            else {
                return "none";
            }
        }
        else {
            return "none";
        }
    }
   
    private ItemStack getItemFrameItem(Location location) {
        Location itemframe_location = location;
        itemframe_location.setY(location.getY() + 1);
       
        ItemFrame itemframe = (ItemFrame) Bukkit.getWorld(location.getWorld().toString()).getBlockAt(itemframe_location);
        return itemframe.getItem();
    }
   
    private void setSign(Location location, String ID) {
        Location sign_location = location;
        sign_location.setY(location.getY() - 1);
       
        Block block = Bukkit.getServer().getWorld(sign_location.getWorld().toString()).getBlockAt(sign_location);
       
        block.setType(Material.SIGN);
       
        Sign sign = (Sign) block.getState();
        sign.setLine(0, "=======");
        sign.setLine(1, ChatColor.WHITE + "Shop");
        sign.setLine(2, ChatColor.WHITE + ID);
        sign.setLine(3, "=======");
    }
}

Error:

Code:

Caused by: java.lang.NullPointerException
        at com.kassestral.plugins.imperium.events.ShopHandler.setSign(ShopHandle
r.java:102) ~[?:?]
        at com.kassestral.plugins.imperium.events.ShopHandler.createShop(ShopHan
dler.java:32) ~[?:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0
_25]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0
_25]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1
.8.0_25]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_25]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.ja
va:292) ~[Craftbukkit.jar:git-Bukkit-1.7.9-R0.2-10-ge6cd8c0-b3096jnks]
        ... 13 more

 

@Kassestral Your using toString on an object and trying to get a world from it. This is completely redundant. You don't need to invoke Bukkit.getWorld when you already have the world stored in your Location object.

 

@Skionz
In all fairness it's 5:40am and I can't think straight xD completely forgot all about that, I'm now getting this error though

Code:

Caused by: java.lang.ClassCastException: org.bukkit.craftbukkit.v1_7_R3.block.Cr
aftBlockState cannot be cast to org.bukkit.block.Sign
        at com.kassestral.plugins.imperium.events.ShopHandler.setSign(ShopHandle
r.java:106) ~[?:?]
        at com.kassestral.plugins.imperium.events.ShopHandler.createShop(ShopHan
dler.java:32) ~[?:?]

 

@Kassestral The block's state isn't an instance of Sign.

 

@Skionz
How can I get the ItemFrame from a location?
I managed to fix the previous error about sign blockstate

 

Block block = Bukkit.getServer().getWorld(sign_location.getWorld().toString()).getBlockAt(sign_location);

why not a simple sign_location.getBlock() ?

if (sign_location.getBlock().getState() instanceof Sign (import the Material.Block){
Sign sign = sign_location.getBlock().getState();

This should totally work if the block casted is a sign.@Kassestral

 

@caderape
Thanks for the help, but if you read my previous comment then you will know I fixed that error, but have a different one

 

@Kassestral He just told you how to fix that. What is the new issue?

 

@Skionz
How can I get the ItemFrame from a location? since the ItemFrame is an instance of an Entity

 

Location loc = your itemframe
for (Entity ent : loc.getChunk().getEntities()){
if (ent.getLocation().equals(loc) && ent instanceof itemframe) {
//do stuff
}
}

May be something liek this ?
@Kassestral

 

Best approach here would be to get the entities in the location's chunk and determine which is closest to the specified location. Keep in mind though you can theoretically have four different ItemFrames in a given block location.