[1.15.2] Capability is null

[xanderindalzone]

I'm getting a null error when I try to get the player's custom capability, I dont know why.... I must have missed something but I dont know where.... if someone could tell where's the problem i would be grateful.

 

Quote

java.lang.NullPointerException: null
    at com.xanderindalzone.customgunsmod.events.client.ClientKeyEvents.AimGun(ClientKeyEvents.java:92) ~[main/:?] {re:classloading}
    at net.minecraftforge.eventbus.ASMEventHandler_8_ClientKeyEvents_AimGun_ClientTickEvent.invoke(.dynamic) ~[?:?] {}
    at net.minecraftforge.eventbus.ASMEventHandler.invoke(ASMEventHandler.java:80) ~[eventbus-2.2.0-service.jar:?] {}
    at net.minecraftforge.eventbus.EventBus.post(EventBus.java:258) ~[eventbus-2.2.0-service.jar:?] {}
    at net.minecraftforge.fml.hooks.BasicEventHooks.onPreClientTick(BasicEventHooks.java:104) ~[forge-1.15.2-31.2.0_mapped_snapshot_20200514-1.15.1-recomp.jar:?] {re:classloading}
    at net.minecraft.client.Minecraft.runTick(Minecraft.java:1387) ~[forge-1.15.2-31.2.0_mapped_snapshot_20200514-1.15.1-recomp.jar:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
    at net.minecraft.client.Minecraft.runGameLoop(Minecraft.java:941) ~[forge-1.15.2-31.2.0_mapped_snapshot_20200514-1.15.1-recomp.jar:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
    at net.minecraft.client.Minecraft.run(Minecraft.java:558) ~[forge-1.15.2-31.2.0_mapped_snapshot_20200514-1.15.1-recomp.jar:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
    at net.minecraft.client.main.Main.main(Main.java:177) ~[forge-1.15.2-31.2.0_mapped_snapshot_20200514-1.15.1-recomp.jar:?] {re:classloading,pl:runtimedistcleaner:A}
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_251] {}
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_251] {}
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_251] {}
    at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_251] {}
    at net.minecraftforge.userdev.FMLUserdevClientLaunchProvider.lambda$launchService$0(FMLUserdevClientLaunchProvider.java:55) ~[forge-1.15.2-31.2.0_mapped_snapshot_20200514-1.15.1-recomp.jar:?] {}
    at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:37) [modlauncher-5.1.0.jar:?] {}
    at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:54) [modlauncher-5.1.0.jar:?] {}
    at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:72) [modlauncher-5.1.0.jar:?] {}
    at cpw.mods.modlauncher.Launcher.run(Launcher.java:81) [modlauncher-5.1.0.jar:?] {}
    at cpw.mods.modlauncher.Launcher.main(Launcher.java:65) [modlauncher-5.1.0.jar:?] {}
    at net.minecraftforge.userdev.LaunchTesting.main(LaunchTesting.java:102) [forge-1.15.2-31.2.0_mapped_snapshot_20200514-1.15.1-recomp.jar:?] {}

 

 

 

Main Mod class

Quote

https://github.com/xanderindalzone/customgunsmod/blob/master/src/main/java/com/xanderindalzone/customgunsmod/CustomGunsMod.java

 

Capability package with providers

Quote

https://github.com/xanderindalzone/customgunsmod/tree/master/src/main/java/com/xanderindalzone/customgunsmod/capabilities

 

Event that attatches capabilities to the player

Quote

https://github.com/xanderindalzone/customgunsmod/blob/master/src/main/java/com/xanderindalzone/customgunsmod/events/GunCapabilityHandler.java

 

Event Handler where I call the capability

Quote

https://github.com/xanderindalzone/customgunsmod/blob/master/src/main/java/com/xanderindalzone/customgunsmod/events/client/ClientKeyEvents.java

 

[Syconn]

Do something like this for AimGun:

Change event to TickEvent.PlayerTickEvent

Use event.player to get player

and get capability like this:

@SubscribeEvent
public static void tick(TickEvent.PlayerTickEvent event) {
   [YourIinterface] data = event.player.getCapability(ProviderGunActions.GUN_ACTIONS_CAP).orElseThrow(IllegalStateException::new);
    
}

[Draco18s]

That's not the problem. That's just a different way to access a capability and ifPresent is perfectly acceptable (and indeed, preferred).

 

I suspect the issue is that ClientTickEvent runs in the main menu before there is a world. Before there is a player and there is no null-check on line 92:

 

Minecraft.getInstance().player.[...]

 

player, there, may be null!

[poopoodice]

Draco is right that the player can be null, the IDE should've told you that.

[xanderindalzone]

Now I'm getting this null exception when I join the world :V (CODE UPDATED on Github)

Quote

java.lang.NullPointerException
    at com.xanderindalzone.customgunsmod.capabilities.providers.ProviderGunActions.<init>(ProviderGunActions.java:19)
    at com.xanderindalzone.customgunsmod.events.GunCapabilityHandler.attachCapability(GunCapabilityHandler.java:71)
    at net.minecraftforge.eventbus.ASMEventHandler_10_GunCapabilityHandler_attachCapability_AttachCapabilitiesEvent.invoke(.dynamic)
    at net.minecraftforge.eventbus.ASMEventHandler.invoke(ASMEventHandler.java:80)
    at net.minecraftforge.eventbus.EventBus.post(EventBus.java:258)
    at net.minecraftforge.event.ForgeEventFactory.gatherCapabilities(ForgeEventFactory.java:564)
    at net.minecraftforge.event.ForgeEventFactory.gatherCapabilities(ForgeEventFactory.java:558)
    at net.minecraftforge.common.capabilities.CapabilityProvider.gatherCapabilities(CapabilityProvider.java:48)
    at net.minecraftforge.common.capabilities.CapabilityProvider.gatherCapabilities(CapabilityProvider.java:44)
    at net.minecraft.entity.Entity.<init>(Entity.java:224)
    at net.minecraft.entity.LivingEntity.<init>(LivingEntity.java:200)
    at net.minecraft.entity.player.PlayerEntity.<init>(PlayerEntity.java:164)
    at net.minecraft.entity.player.ServerPlayerEntity.<init>(ServerPlayerEntity.java:161)
    at net.minecraft.server.management.PlayerList.createPlayerForUser(PlayerList.java:395)
    at net.minecraft.network.login.ServerLoginNetHandler.tryAcceptPlayer(ServerLoginNetHandler.java:120)
    at net.minecraft.network.login.ServerLoginNetHandler.tick(ServerLoginNetHandler.java:64)
    at net.minecraft.network.NetworkManager.tick(NetworkManager.java:246)
    at net.minecraft.network.NetworkSystem.tick(NetworkSystem.java:152)
    at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:903)
    at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:821)
    at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:120)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:662)
    at java.lang.Thread.run(Unknown Source)
 

 

 

Isnt this the way it has to be implemented?

Quote

    @CapabilityInject(IGunActions.class)
    public static final Capability<IGunActions> GUN_ACTIONS_CAP = null;

    private LazyOptional<IGunActions> instance = LazyOptional.of(GUN_ACTIONS_CAP::getDefaultInstance);

 

PD: I think I got this line from another post.

[xanderindalzone]

29 minutes ago, diesieben07 said:

This method is never called (you don't register it as an event handler) and thus your capability is never registered. Therefor your @CapabilityInject field stays null.

Oh yeah, I'm dumb, I copypasted the code and forgot to change the method name in the parameter :P, thx XD

I sometimes change code too fast that I dont realize of these silly mistakes XD

Its now joining the world without crashes  thx