Command giving an error

I use this class to set a player's rank stored in a HashMap<UUID, String>.

Code:java

 
public class RankCommand implements CommandExecutor{
 
    Main plugin;
 
    public RankCommand(Main instance){
        plugin = instance;
    }
 
    public boolean onCommand(CommandSender sender, Command cmd, String commandLabel, String[] args){
        if(cmd.getName().equalsIgnoreCase("setrank")){
            if(args.length == 0){
                sender.sendMessage(ChatColor.GRAY + "Please use " + ChatColor.YELLOW + "/setrank <player> <rank>" + ChatColor.GRAY + ".");
                return true;
            }
            if(args.length == 1){
                sender.sendMessage(ChatColor.GRAY + "Please specify a " + ChatColor.YELLOW + "Rank" + ChatColor.GRAY + ".");
                return true;
            }
            if(args.length == 2){
 
                Player target = Bukkit.getServer().getPlayer(args[0]);
 
                if(target == null){
                    sender.sendMessage(ChatColor.GRAY + "Could not find the player " + ChatColor.YELLOW + args[0]);
                    return true;
                }
 
                if(args[1].equalsIgnoreCase("user")){
                    plugin.rank.put(target.getUniqueId(), "user");
                    sender.sendMessage(ChatColor.GRAY + "Player " + ChatColor.YELLOW + target.getName() + ChatColor.GRAY + "is now an " + ChatColor.YELLOW + "user" + ChatColor.GRAY + ".");
                    return true;
                }
 
                if(args[1].equalsIgnoreCase("admin")){
                    plugin.rank.put(target.getUniqueId(), "admin");
                    sender.sendMessage(ChatColor.GRAY + "Player " + ChatColor.YELLOW + target.getName() + ChatColor.GRAY + "is now an " + ChatColor.YELLOW + "admin" + ChatColor.GRAY + ".");
                    return true;
                }
            }
            if(args.length > 2){
                sender.sendMessage(ChatColor.GRAY + "Please use " + ChatColor.YELLOW + "/setrank <player> <rank>" + ChatColor.GRAY + ".");
                return true;
            }
        }
        return true;
    }
}
 
 

it worked until I tried to do /setrank doubtstand user and it gave me an error:

Code:java

 
00:00:38 [ERROR] null
00:00:38 org.bukkit.command.CommandException: Unhandled exception executing command 'setrank' in plugin DevTest v1.0
00:00:38 at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[spigot.jar:git-Spigot-044d928-e8c6403]
00:00:38 at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) ~[spigot.jar:git-Spigot-044d928-e8c6403]
00:00:38 at org.bukkit.craftbukkit.v1_8_R3.CraftServer.dispatchCommand(CraftServer.java:642) ~[spigot.jar:git-Spigot-044d928-e8c6403]
00:00:38 at net.minecraft.server.v1_8_R3.PlayerConnection.handleCommand(PlayerConnection.java:1135) [spigot.jar:git-Spigot-044d928-e8c6403]
00:00:38 at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:970) [spigot.jar:git-Spigot-044d928-e8c6403]
00:00:38 at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(PacketPlayInChat.java:45) [spigot.jar:git-Spigot-044d928-e8c6403]
00:00:38 at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(PacketPlayInChat.java:1) [spigot.jar:git-Spigot-044d928-e8c6403]
00:00:38 at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:13) [spigot.jar:git-Spigot-044d928-e8c6403]
00:00:38 at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.8.0_51]
00:00:38 at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_51]
00:00:38 at net.minecraft.server.v1_8_R3.SystemUtils.a(SystemUtils.java:19) [spigot.jar:git-Spigot-044d928-e8c6403]
00:00:38 at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:718) [spigot.jar:git-Spigot-044d928-e8c6403]
00:00:38 at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:367) [spigot.jar:git-Spigot-044d928-e8c6403]
00:00:38 at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:657) [spigot.jar:git-Spigot-044d928-e8c6403]
00:00:38 at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:560) [spigot.jar:git-Spigot-044d928-e8c6403]
00:00:38 at java.lang.Thread.run(Unknown Source) [?:1.8.0_51]
00:00:38 Caused by: java.lang.NullPointerException
00:00:38 at commands.RankCommand.onCommand(RankCommand.java:40) ~[?:?]
00:00:38 at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[spigot.jar:git-Spigot-044d928-e8c6403]
00:00:38 ... 15 more
 

So it gives an error when adding "user" to the hashmap, but how do I fix this?

Thanks, Sten.

 

@Doubtstand

Something on line 40 is null, as per:

I'm willing to bet it's "rank," and that really shouldn't be a public member anyway.

 

Also please enhance your code's efficiency by using if ,else if, else statements, See

args.length cannot be both 0, 1 and 2 so here an if else if statement would be good.

 

Plugin main; rank (might) be null, is it possible you could post your main class?

 

That was the case, fixed it by now but thanks anyways