Retrieve key with value in a HashMap, NPE

Hello guys,

I'm trying to randomly loop through my HashMap, get a value, then get the key from said value. Though there doesn't seem to be a way to do this. So I've tried comparing each Key to the value and see if it maps up. Though my logic may just be wrong on this one, but I have a NPE on what I'd think shouldn't be null.

Here it is in pastebin
http://pastebin.com/BVCV1ALb

Code:

package com.thecollapsemc.jobs;

import java.util.Random;

import org.bukkit.Location;
import org.bukkit.Material;
import org.bukkit.command.Command;
import org.bukkit.command.CommandExecutor;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import org.bukkit.inventory.ItemStack;

import net.md_5.bungee.api.ChatColor;

public class NewPackageCMD implements CommandExecutor {

    @Override
    public boolean onCommand(CommandSender s, Command arg1, String arg2, String[] args) {
        if(s instanceof Player){
            Player p = (Player) s;
            //They are not a postman, don't let them continue
            if(Jobs.getJobForPlayer(p) != "postman"){
                p.sendMessage(ChatColor.RED + "This command is for Postmen only!");
                return true;
            }else{
                for(String loc : Jobs.locations.keySet()){
                    //This would be the potential package
                    ItemStack potentialPackage = ItemUtils.createItem(Material.PAPER,ChatColor.YELLOW + "Drop off at the " + loc.toLowerCase(), ChatColor.GRAY+
                            "Go to the " + loc.toLowerCase() + " with this, and type /dropoff");
                    //They already have a package, don't give them a new one.
                    if(p.getInventory().contains(potentialPackage)){
                        p.sendMessage(ChatColor.RED + "You already have a package to deliver!");
                    }else{
                        //Randomly select a location from my HashMap locations that stores a <String, Location>
                        Location newLoc = Jobs.locations.get(new Random().nextInt(Jobs.locations.size()));
                        //This is the part that I think is causing the trouble, 
                        //I tried comparing all the locations in the HashMap to see if they were equal to the new one
                        Location oldLoc = Jobs.locations.get(loc);
                   //This is where the NPE is     if(Jobs.locations.get(loc).getX() == newLoc.getX() && oldLoc.getY() == newLoc.getY() && oldLoc.getZ() == newLoc.getZ()){
                            p.getInventory().addItem(potentialPackage);
                           
                        }else{
                            p.sendMessage(ChatColor.RED + "Oh no, something has gone wrong and we couldn't find a new package for you!");
                        }
                    }
                }
            }
        }
        return true;
    }

}

Thanks for the help,

 

@PumpMelon
Instead of looping through all the values, and trying to find the key that matches, why not loop through the entries? Entries contain both a key and the linked value. Use HashMap#entrySet() to get the entry set.