Setting display name to team prefix

I am making a plugin that gets a players display name, creates a scoreboard team, and sets their display name as the team prefix. From what I believe, that would make their chat prefix and all that appear above them. The plugin loads fine, till I join I get an EventException error.

Here is main class:

Code:

package com.gmail.ubtuub;

import org.bukkit.Bukkit;
import org.bukkit.plugin.java.JavaPlugin;
import org.bukkit.scoreboard.Scoreboard;

public class Main extends JavaPlugin{
   
    public Scoreboard sb;
   
    @Override
    public void onEnable(){
        getLogger().info("Enabled!");
        getServer().getPluginManager().registerEvents(new Join(), this);
        sb = Bukkit.getScoreboardManager().getMainScoreboard();
    }
   
    @Override
    public void onDisable(){
        getLogger().info("Disabled!");
    }
   

}

Here is Event class:

Code:

package com.gmail.ubtuub;

import org.bukkit.event.EventHandler;
import org.bukkit.event.EventPriority;
import org.bukkit.event.Listener;
import org.bukkit.event.player.PlayerJoinEvent;
import org.bukkit.scoreboard.Team;

public class Join implements Listener{
   
    public Main plugin;
   
    @EventHandler(priority = EventPriority.HIGHEST)
    public void onJoin(PlayerJoinEvent e){
        Team t = plugin.sb.registerNewTeam(e.getPlayer().getName());
        t.setPrefix(e.getPlayer().getDisplayName());
        t.addPlayer(e.getPlayer());
    }
   
}

Please help ASAP. Thank you!

 

@JpPlugins

The only thing that will help is the error itself.

 

Right, here it is @mythbusterma

Code:

[23:22:36 ERROR]: Could not pass event PlayerJoinEvent to MineQuarters-NameTag v1.0
org.bukkit.event.EventException
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:305) ~[bukkit.jar:git-Spigot-c136710-350cb99]
    at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[bukkit.jar:git-Spigot-c136710-350cb99]
    at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [bukkit.jar:git-Spigot-c136710-350cb99]
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [bukkit.jar:git-Spigot-c136710-350cb99]
    at net.minecraft.server.v1_8_R2.PlayerList.onPlayerJoin(PlayerList.java:296) [bukkit.jar:git-Spigot-c136710-350cb99]
    at net.minecraft.server.v1_8_R2.PlayerList.a(PlayerList.java:156) [bukkit.jar:git-Spigot-c136710-350cb99]
    at net.minecraft.server.v1_8_R2.LoginListener.b(LoginListener.java:144) [bukkit.jar:git-Spigot-c136710-350cb99]
    at net.minecraft.server.v1_8_R2.LoginListener.c(LoginListener.java:54) [bukkit.jar:git-Spigot-c136710-350cb99]
    at net.minecraft.server.v1_8_R2.NetworkManager.a(NetworkManager.java:231) [bukkit.jar:git-Spigot-c136710-350cb99]
    at net.minecraft.server.v1_8_R2.ServerConnection.c(ServerConnection.java:148) [bukkit.jar:git-Spigot-c136710-350cb99]
    at net.minecraft.server.v1_8_R2.MinecraftServer.A(MinecraftServer.java:809) [bukkit.jar:git-Spigot-c136710-350cb99]
    at net.minecraft.server.v1_8_R2.DedicatedServer.A(DedicatedServer.java:368) [bukkit.jar:git-Spigot-c136710-350cb99]
    at net.minecraft.server.v1_8_R2.MinecraftServer.z(MinecraftServer.java:651) [bukkit.jar:git-Spigot-c136710-350cb99]
    at net.minecraft.server.v1_8_R2.MinecraftServer.run(MinecraftServer.java:554) [bukkit.jar:git-Spigot-c136710-350cb99]
    at java.lang.Thread.run(Thread.java:695) [?:1.6.0_65]
Caused by: java.lang.NullPointerException
    at com.gmail.ubtuub.Join.onJoin(Join.java:15) ~[?:?]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.6.0_65]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ~[?:1.6.0_65]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) ~[?:1.6.0_65]
    at java.lang.reflect.Method.invoke(Method.java:597) ~[?:1.6.0_65]
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:301) ~[bukkit.jar:git-Spigot-c136710-350cb99]
    ... 14 more

 

This throws a null because you haven't set the MainScoreboard yet. Just make sure you initialize the MainScoreboard before you try to grab it

 

@JpPlugins That's not how this works either. The prefix is shown before the name. Useful for colors or prefixes/suffixes. Not useful for custom chat name formatting because the original name is still shown. Look into TagAPI.

 

@JpPlugins
'plugin' is not initialized in your listener class. Therefore its null.

 

Thanks you guys @MexMaster @pie_flavor @Msrules123
I have recoded the entire plugin so that you can add players to configured groups with prefixes and it seems to work perfect