Solved Bug in my Code?

Hey, Im working on a plugin, and the following code is not working. This will be the first plugin i have made, so im new to the methods of doing things with bukkit in Java. This code for the command /mcportals outputs an internal error message when i run it with any arguments, but the error just says Null. It uses a HashMap to store temporary data about wether or not the player is currently creating a portal. Ive tried checking to make sure that the key in the HashMap exists, but that doesnt change anything. If you know a better way for storing this temporary data, im happy to change it.

PHP:

package me.mezzadev.mcportals.command;

import java.util.HashMap;
import org.bukkit.ChatColor;
import org.bukkit.command.Command;
import org.bukkit.command.CommandExecutor;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import me.mezzadev.mcportals.Main;

public class MainCommand implements CommandExecutor {
   
    @SuppressWarnings("unused")
    private Main plugin;
   
    private HashMap<String,Boolean> Marking = new HashMap<String,Boolean>();
    private HashMap<String,String> PortalMarking = new HashMap<String,String>();
   
    public MainCommand(Main plugin) {
        this.plugin = plugin;
        plugin.getCommand("mcportals").setExecutor(this);
    }
   
    @Override
    public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {
        if (!(sender instanceof Player)) {
            sender.sendMessage("Only Players may use this command.");
            return false;
        }
       
        Player p = (Player) sender;
       
        if (args.length == 0) {
           
            // Send list of commands
           
            p.sendMessage(ChatColor.AQUA + "                    -=+=- " + ChatColor.AQUA + "" + ChatColor.BOLD + " MC Portals " + ChatColor.RESET + ChatColor.AQUA + " -=+=-");
            p.sendMessage(ChatColor.BLUE + "                 A list of Commands for MC Portals");
            p.sendMessage("");
            p.sendMessage(ChatColor.AQUA + " /mcportals create <name>" + ChatColor.BLUE + " Create a new Portal");
            p.sendMessage("");
           
            return false;
        }
       
        if (args.length == 1) {
            if(args[0].equals("cancel")) {
                if (!(Marking.get(p.getUniqueId().toString()).equals(null)) && Marking.get(p.getUniqueId().toString()).equals(true)) {
                    p.sendMessage(ChatColor.AQUA + "You cancelled the creation of Portal " + ChatColor.BLUE + ChatColor.BOLD + PortalMarking.get(p.getUniqueId().toString()));
                    p.getInventory().removeItem(Marker.getMarker());
                    Marking.remove(p.getUniqueId().toString());
                    PortalMarking.remove(p.getUniqueId().toString());
                    return false;
                }
               
                p.sendMessage(ChatColor.AQUA + "You are not creating a Portal");
               
                return false;
            }
        }
       
        if (args.length == 2) {
            if (args[0].equals("create")) {
                if ((!Marking.get(p.getUniqueId().toString()).equals(null)) && Marking.get(p.getUniqueId().toString()).equals(false)) {
                    String name = args[1];
                   
                    p.sendMessage(ChatColor.BLUE + "                          -=+=-");
                    p.sendMessage(ChatColor.AQUA + "Creating Portal " + ChatColor.BLUE + ChatColor.BOLD + name);
                    p.sendMessage(ChatColor.AQUA + "Use the " + ChatColor.BLUE + ChatColor.BOLD + "Marker " + ChatColor.RESET + ChatColor.AQUA + "To mark the Portal's corners " + ChatColor.BLUE + ChatColor.BOLD + "(Right - Click)");
                    p.sendMessage(ChatColor.AQUA + "You can cancel at any time with " + ChatColor.BLUE + "/mcportals cancel");
                    p.sendMessage(ChatColor.BLUE + "                          -=+=-");
                   
                    if (!(p.getInventory().containsAtLeast(Marker.getMarker(), 1))) {
                        p.getInventory().addItem(Marker.getMarker());
                    }
                   
                    Marking.put(p.getUniqueId().toString(), true);
                    PortalMarking.put(p.getUniqueId().toString(), name);
               
                    return false;
                }
               
                p.sendMessage(ChatColor.AQUA + "You are already creating the portal " + ChatColor.BLUE + ChatColor.BOLD + PortalMarking.get(p.getUniqueId().toString()));
                p.sendMessage(ChatColor.AQUA + "You can cancel it with " + ChatColor.BLUE + "/mcportals cancel" + ChatColor.AQUA + "or complete it with " + ChatColor.BLUE + "/mcportals complete");
               
                return false;
            }
           
            return false;
        }
       
        return false;
    }
}


Thanks for any help.

 

Have you registered the command in the plugin.yml?

Also, if you get a stack trace, please post it.

 

Yeah, i have registered it. The command was working fine when i was not trying to store temporary data with a HashMap, and it is registered in the yml. Here is the full error message on the console:

Code:

[ERROR] null

org.bukkit.command.CommandException: Unhandled exception executing command 'mcp' in plugin McPortals v1.0

at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[craftbukkit-1.13.2.jar:git-Bukkit-a3c2ec0]

at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:138) ~[craftbukkit-1.13.2.jar:git-Bukkit-a3c2ec0]

at org.bukkit.craftbukkit.v1_13_R2.CraftServer.dispatchCommand(CraftServer.java:682) ~[craftbukkit-1.13.2.jar:git-Bukkit-a3c2ec0]

at net.minecraft.server.v1_13_R2.PlayerConnection.handleCommand(PlayerConnection.java:1580) ~[craftbukkit-1.13.2.jar:git-Bukkit-a3c2ec0]

at net.minecraft.server.v1_13_R2.PlayerConnection.a(PlayerConnection.java:1440) ~[craftbukkit-1.13.2.jar:git-Bukkit-a3c2ec0]

at net.minecraft.server.v1_13_R2.PacketPlayInChat.a(SourceFile:37) ~[craftbukkit-1.13.2.jar:git-Bukkit-a3c2ec0]

at net.minecraft.server.v1_13_R2.PacketPlayInChat.a(SourceFile:9) ~[craftbukkit-1.13.2.jar:git-Bukkit-a3c2ec0]

at net.minecraft.server.v1_13_R2.PlayerConnectionUtils.a(SourceFile:10) ~[craftbukkit-1.13.2.jar:git-Bukkit-a3c2ec0]

at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_172]

at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_172]

at net.minecraft.server.v1_13_R2.SystemUtils.a(SourceFile:199) [craftbukkit-1.13.2.jar:git-Bukkit-a3c2ec0]

at net.minecraft.server.v1_13_R2.MinecraftServer.b(MinecraftServer.java:843) [craftbukkit-1.13.2.jar:git-Bukkit-a3c2ec0]

at net.minecraft.server.v1_13_R2.DedicatedServer.b(DedicatedServer.java:382) [craftbukkit-1.13.2.jar:git-Bukkit-a3c2ec0]

at net.minecraft.server.v1_13_R2.MinecraftServer.a(MinecraftServer.java:796) [craftbukkit-1.13.2.jar:git-Bukkit-a3c2ec0]

at net.minecraft.server.v1_13_R2.MinecraftServer.run(MinecraftServer.java:699) [craftbukkit-1.13.2.jar:git-Bukkit-a3c2ec0]

at java.lang.Thread.run(Thread.java:748) [?:1.8.0_172]

Caused by: java.lang.NullPointerException

at me.mezzadev.mcportals.command.MainCommand.onCommand(MainCommand.java:64) ~[?:?]

at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[craftbukkit-1.13.2.jar:git-Bukkit-a3c2ec0]

... 15 more

Turns out ive been fiddling with the code and ive managed to get it working myself. The problem was as id suspected, there was an error because i was trying to check the value of a key in the HashMap when the key i was finding the value of didnt exist. Ive fixed this by adding a few extra tests for cases where the key didnt exist. Here is my updated code:

PHP:

package me.mezzadev.mcportals.command;

import java.util.HashMap;
import org.bukkit.ChatColor;
import org.bukkit.command.Command;
import org.bukkit.command.CommandExecutor;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import me.mezzadev.mcportals.Main;

public class MainCommand implements CommandExecutor {
   
    @SuppressWarnings("unused")
    private Main plugin;
   
    private HashMap<String,Boolean> Marking = new HashMap<String,Boolean>();
    private HashMap<String,String> PortalMarking = new HashMap<String,String>();
   
    public MainCommand(Main plugin) {
        this.plugin = plugin;
        plugin.getCommand("mcportals").setExecutor(this);
    }
   
    @Override
    public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {
        if (!(sender instanceof Player)) {
            sender.sendMessage("Only Players may use this command.");
            return false;
        }
       
        Player p = (Player) sender;
       
        if (args.length == 0) {
           
            // Send list of commands
           
            p.sendMessage(ChatColor.AQUA + "                    -=+=- " + ChatColor.AQUA + "" + ChatColor.BOLD + " MC Portals " + ChatColor.RESET + ChatColor.AQUA + " -=+=-");
            p.sendMessage(ChatColor.BLUE + "                 A list of Commands for MC Portals");
            p.sendMessage("");
            p.sendMessage(ChatColor.AQUA + " /mcportals create <name>" + ChatColor.BLUE + " Create a new Portal");
            p.sendMessage("");
           
            return false;
        }
       
        if (args.length == 1) {
            if(args[0].equals("cancel")) {
                if (!(Marking.containsKey(p.getUniqueId().toString()))) {
                    p.sendMessage(ChatColor.AQUA + "You are not creating a Portal");
                    return false;
                }
               
                if (Marking.get(p.getUniqueId().toString()).equals(true)) {
                    p.sendMessage(ChatColor.AQUA + "You cancelled the creation of Portal " + ChatColor.BLUE + ChatColor.BOLD + PortalMarking.get(p.getUniqueId().toString()));
                    p.getInventory().removeItem(Marker.getMarker());
                    Marking.remove(p.getUniqueId().toString());
                    PortalMarking.remove(p.getUniqueId().toString());
                    return false;
                }
                return false;
            }
        }
       
        if (args.length == 2) {
            if (args[0].equals("create")) {
                if (Marking.containsKey(p.getUniqueId().toString()) || (Marking.containsKey(p.getUniqueId().toString()) && !(Marking.get(p.getUniqueId().toString()).equals(null)))) {
                    p.sendMessage(ChatColor.AQUA + "You are already creating the portal " + ChatColor.BLUE + ChatColor.BOLD + PortalMarking.get(p.getUniqueId().toString()));
                    p.sendMessage(ChatColor.AQUA + "You can cancel it with " + ChatColor.BLUE + "/mcportals cancel" + ChatColor.AQUA + "or complete it with " + ChatColor.BLUE + "/mcportals complete");
                   
                    return false;
                }
               
                if (!(Marking.containsKey(p.getUniqueId().toString())) || Marking.get(p.getUniqueId().toString()).equals(false)) {
                    String name = args[1];
                   
                    p.sendMessage(ChatColor.BLUE + "                          -=+=-");
                    p.sendMessage(ChatColor.AQUA + "Creating Portal " + ChatColor.BLUE + ChatColor.BOLD + name);
                    p.sendMessage(ChatColor.AQUA + "Use the " + ChatColor.BLUE + ChatColor.BOLD + "Marker " + ChatColor.RESET + ChatColor.AQUA + "To mark the Portal's corners " + ChatColor.BLUE + ChatColor.BOLD + "(Right - Click)");
                    p.sendMessage(ChatColor.AQUA + "You can cancel at any time with " + ChatColor.BLUE + "/mcportals cancel");
                    p.sendMessage(ChatColor.BLUE + "                          -=+=-");
                   
                    if (!(p.getInventory().containsAtLeast(Marker.getMarker(), 1))) {
                        p.getInventory().addItem(Marker.getMarker());
                    }
                   
                    Marking.put(p.getUniqueId().toString(), true);
                    PortalMarking.put(p.getUniqueId().toString(), name);
               
                    return false;
                }
               
                return false;
            }
           
            return false;
        }
       
        return false;
    }
}


EDIT by Moderator: merged posts, please use the edit button instead of double posting.