NullPointer on Debugging

I have the Inventory#addItem method trying to add an item to a player's inventory but I get a NullPointer pointing at the line.

When debugging I sysouted the ItemStack and then it shot me a nullpointer on sysouting.

StackTrace:

Code:

[18:14:27] [Server thread/WARN]: [PrisonProfessional] Task #13 for PrisonProfessional v1.0 generated an exception
java.lang.NullPointerException
    at org.bukkit.craftbukkit.v1_8_R2.inventory.CraftMetaItem.serializeEnchantments(CraftMetaItem.java:888) ~[craftbukkit.jar:git-Spigot-26dfd01-5cb9b70]
    at org.bukkit.craftbukkit.v1_8_R2.inventory.CraftMetaItem.serialize(CraftMetaItem.java:856) ~[craftbukkit.jar:git-Spigot-26dfd01-5cb9b70]
    at org.bukkit.craftbukkit.v1_8_R2.inventory.CraftMetaItem.serialize(CraftMetaItem.java:842) ~[craftbukkit.jar:git-Spigot-26dfd01-5cb9b70]
    at org.bukkit.craftbukkit.v1_8_R2.inventory.CraftMetaItem.toString(CraftMetaItem.java:934) ~[craftbukkit.jar:git-Spigot-26dfd01-5cb9b70]
    at java.lang.String.valueOf(Unknown Source) ~[?:1.8.0_25]
    at java.lang.StringBuilder.append(Unknown Source) ~[?:1.8.0_25]
    at org.bukkit.inventory.ItemStack.toString(ItemStack.java:304) ~[craftbukkit.jar:git-Spigot-26dfd01-5cb9b70]
    at java.lang.String.valueOf(Unknown Source) ~[?:1.8.0_25]
    at java.lang.StringBuilder.append(Unknown Source) ~[?:1.8.0_25]
    at co.netspeed.prisonprofessional.methods.QuickMethods.addSlot(QuickMethods.java:552) ~[?:?]
    at co.netspeed.prisonprofessional.api.PAchievementsCore$1.run(PAchievementsCore.java:401) ~[?:?]
    at org.bukkit.craftbukkit.v1_8_R2.scheduler.CraftTask.run(CraftTask.java:71) ~[craftbukkit.jar:git-Spigot-26dfd01-5cb9b70]
    at org.bukkit.craftbukkit.v1_8_R2.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:350) [craftbukkit.jar:git-Spigot-26dfd01-5cb9b70]
    at net.minecraft.server.v1_8_R2.MinecraftServer.A(MinecraftServer.java:718) [craftbukkit.jar:git-Spigot-26dfd01-5cb9b70]
    at net.minecraft.server.v1_8_R2.DedicatedServer.A(DedicatedServer.java:368) [craftbukkit.jar:git-Spigot-26dfd01-5cb9b70]
    at net.minecraft.server.v1_8_R2.MinecraftServer.z(MinecraftServer.java:651) [craftbukkit.jar:git-Spigot-26dfd01-5cb9b70]
    at net.minecraft.server.v1_8_R2.MinecraftServer.run(MinecraftServer.java:554) [craftbukkit.jar:git-Spigot-26dfd01-5cb9b70]
    at java.lang.Thread.run(Unknown Source)

The line it is pointing at is the sysout lining and I don't understand why that is null either. If the ItemStack is null then it should at least print out null.

My Question: Why is this NullPointing on a System.out line?

Code:

System.out.println(i+" : "+im);
p.getInventory().setItem(i, im);

 

I'm assuming it's because you're indirectly calling the toString() method on the ItemStack object, which is null.

 

It's obviously returning your itemstack null I suggest you fix your itemstack.