Solved String not saving to list...

I know this might sound as stupid just like the title but I'm pretty sure I'm doing this right:

Code:

// This shortened code I will provide longer if needed
public static List<String> players = new List<String>();

// Later on in a Sell Class
Core.players.add(p.getName()); 

But yet when I use /bmsi 1 1 it gives:
1. It gives an NPE for both parts for adding the player name, just 1 and > 1 item
2. I commented out the part with the "Core.players.add(p.getName()); " but doesn't remove that one item


Heres the error:

Code:

[23:13:47 ERROR]: null 
org.bukkit.command.CommandException: Unhandled exception executing command 'bmsi' in plugin BlackMarket v1.0.9         
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[craftbukkit-1.11.2.jar:git-Bukkit-6e3cec8]         
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:140) ~[craftbukkit-1.11.2.jar:git-Bukkit-6e3cec8]        
 at org.bukkit.craftbukkit.v1_11_R1.CraftServer.dispatchCommand(CraftServer.java:629) ~[craftbukkit-1.11.2.jar:git-Bukkit-6e3cec8]         
at net.minecraft.server.v1_11_R1.PlayerConnection.handleCommand(PlayerConnection.java:1295) [craftbukkit-1.11.2.jar:git-Bukkit-6e3cec8]        
 at net.minecraft.server.v1_11_R1.PlayerConnection.a(PlayerConnection.java:1155) [craftbukkit-1.11.2.jar:git-Bukkit-6e3cec8]         
at net.minecraft.server.v1_11_R1.PacketPlayInChat.a(SourceFile:37) [craftbukkit-1.11.2.jar:git-Bukkit-6e3cec8]        
 at net.minecraft.server.v1_11_R1.PacketPlayInChat.a(SourceFile:9) [craftbukkit-1.11.2.jar:git-Bukkit-6e3cec8]         
at net.minecraft.server.v1_11_R1.PlayerConnectionUtils$1.run(SourceFile:13) [craftbukkit-1.11.2.jar:git-Bukkit-6e3cec8]         
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_112]         
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_112]         
at net.minecraft.server.v1_11_R1.SystemUtils.a(SourceFile:46) [craftbukkit-1.11.2.jar:git-Bukkit-6e3cec8]  
at net.minecraft.server.v1_11_R1.MinecraftServer.D(MinecraftServer.java:695) [craftbukkit-1.11.2.jar:git-Bukkit-6e3cec8]         
at net.minecraft.server.v1_11_R1.DedicatedServer.D(DedicatedServer.java:360) [craftbukkit-1.11.2.jar:git-Bukkit-6e3cec8]         
at net.minecraft.server.v1_11_R1.MinecraftServer.C(MinecraftServer.java:650) [craftbukkit-1.11.2.jar:git-Bukkit-6e3cec8]         
at net.minecraft.server.v1_11_R1.MinecraftServer.run(MinecraftServer.java:554) [craftbukkit-1.11.2.jar:git-Bukkit-6e3cec8]        
 at java.lang.Thread.run(Thread.java:745) [?:1.8.0_112] Caused by: java.lang.NullPointerException         
at com.gc.blackmarket.commands.Sell.onCommand(Sell.java:87) ~[?:?]         
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[craftbukkit-1.11.2.jar:git-Bukkit-6e3cec8]         
... 15 more

Line 87:

Code:

Core.players.add(p.getName()); 

Does anyone know whats wrong?

~ AdamDev

P.S There should be another post coming up very shortly from me.

 

@AdamDev
'new List<String>()' should not work. List is an interface and cannot be instantiated. Can you show us your actual code?

 

@AlvinB
Oops. I meant to write new ArrayList<String>();

I'll send you my code later since I'm not on my computer.

Edit:
Wow, can't even believe that I didn't notice it...

I put

Code:

public static List<String> players;

// instead of:
public static List<String> players = new ArrayList<String>();

Thanks for your help anyway.