Null Pointer Exception on NBT

[TLHPoE]

I'm getting a null pointer exception on line 30. I don't see anything wrong?

 

http://pastebin.com/cYQraBDd

[Lycanus Darkbinder]

Are you sure it's line 30? You're probably getting a NULL for the World

 

World world = player.getEntityWorld();
NBTTagCompound nbt = world.getWorldInfo().getPlayerNBTTagCompound();

 

By the way, what version of Minecraft are you writing for? Can't you just use player.worldObj?

[TLHPoE]

I did the worldObj here: http://pastebin.com/Q9mbbL1j

 

 

 

Here's the new error that pops up: http://pastebin.com/ANLXMWvC

[Lycanus Darkbinder]

Hmm, can you try checking if the player object is valid?

 

EntityPlayer player = (EntityPlayer) event.entity;

if (player != null)
{
    // do stuff
}
else
{
    // oops
}

 

Another thing you could try is just using the entity itself since EntityJoinWorldEvent has a public field called world

 

if (event.entity instanceof EntityPlayer)
{
    event.entity.world;
}
else
{
    // oops
}

[TLHPoE]

Isn't

 

EntityPlayer player = (EntityPlayer)event.entity;

if(player != null){}

 

the same as

 

if (event.entity instanceof EntityPlayer){}

 

 

 

 

 

Also, I did that event.world, I created a world and crashed.

 

Error

 

 

2013-09-13 22:51:32 [iNFO] [sTDERR] java.lang.NullPointerException

2013-09-13 22:51:32 [iNFO] [sTDERR] at terramagna.utils.PlayerStatsUtil.onEntityJoinWorld(PlayerStatsUtil.java:27)

2013-09-13 22:51:32 [iNFO] [sTDERR] at net.minecraftforge.event.ASMEventHandler_5_PlayerStatsUtil_onEntityJoinWorld_EntityJoinWorldEvent.invoke(.dynamic)

2013-09-13 22:51:32 [iNFO] [sTDERR] at net.minecraftforge.event.ASMEventHandler.invoke(ASMEventHandler.java:39)

2013-09-13 22:51:32 [iNFO] [sTDERR] at net.minecraftforge.event.EventBus.post(EventBus.java:108)

2013-09-13 22:51:32 [iNFO] [sTDERR] at net.minecraft.world.World.spawnEntityInWorld(World.java:1572)

2013-09-13 22:51:32 [iNFO] [sTDERR] at net.minecraft.server.management.ServerConfigurationManager.playerLoggedIn(ServerConfigurationManager.java:267)

2013-09-13 22:51:32 [iNFO] [sTDERR] at net.minecraft.server.management.ServerConfigurationManager.initializeConnectionToPlayer(ServerConfigurationManager.java:136)

2013-09-13 22:51:32 [iNFO] [sTDERR] at net.minecraft.server.integrated.IntegratedServerListenThread.networkTick(IntegratedServerListenThread.java:97)

2013-09-13 22:51:32 [iNFO] [sTDERR] at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:689)

2013-09-13 22:51:32 [iNFO] [sTDERR] at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:585)

2013-09-13 22:51:32 [iNFO] [sTDERR] at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:129)

2013-09-13 22:51:32 [iNFO] [sTDERR] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:482)

2013-09-13 22:51:32 [iNFO] [sTDERR] at net.minecraft.server.ThreadMinecraftServer.run(ThreadMinecraftServer.java:16)

2013-09-13 22:51:32 [sEVERE] [Minecraft-Server] Encountered an unexpected exception NullPointerException

java.lang.NullPointerException

at terramagna.utils.PlayerStatsUtil.onEntityJoinWorld(PlayerStatsUtil.java:27)

at net.minecraftforge.event.ASMEventHandler_5_PlayerStatsUtil_onEntityJoinWorld_EntityJoinWorldEvent.invoke(.dynamic)

at net.minecraftforge.event.ASMEventHandler.invoke(ASMEventHandler.java:39)

at net.minecraftforge.event.EventBus.post(EventBus.java:108)

at net.minecraft.world.World.spawnEntityInWorld(World.java:1572)

at net.minecraft.server.management.ServerConfigurationManager.playerLoggedIn(ServerConfigurationManager.java:267)

at net.minecraft.server.management.ServerConfigurationManager.initializeConnectionToPlayer(ServerConfigurationManager.java:136)

at net.minecraft.server.integrated.IntegratedServerListenThread.networkTick(IntegratedServerListenThread.java:97)

at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:689)

at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:585)

at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:129)

at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:482)

at net.minecraft.server.ThreadMinecraftServer.run(ThreadMinecraftServer.java:16)

2013-09-13 22:51:32 [sEVERE] [Minecraft-Server] This crash report has been saved to: C:\Users\Kavin\Desktop\Programming\Java\Modding\Operation Terra Magna\forge859\mcp\jars\.\crash-reports\crash-2013-09-13_22.51.32-server.txt

2013-09-13 22:51:32 [iNFO] [Minecraft-Server] Stopping server

2013-09-13 22:51:32 [iNFO] [Minecraft-Server] Saving players

2013-09-13 22:51:32 [iNFO] [Minecraft-Server] Player951 left the game

2013-09-13 22:51:32 [iNFO] [Minecraft-Server] Saving worlds

2013-09-13 22:51:32 [iNFO] [Minecraft-Server] Saving chunks for level 'New World'/Overworld

2013-09-13 22:51:32 [iNFO] [sTDOUT] ---- Minecraft Crash Report ----

2013-09-13 22:51:32 [iNFO] [sTDOUT] // I'm sorry, Dave.

2013-09-13 22:51:32 [iNFO] [sTDOUT]

2013-09-13 22:51:32 [iNFO] [sTDOUT] Time: 9/13/13 10:51 PM

2013-09-13 22:51:32 [iNFO] [sTDOUT] Description: Exception in server tick loop

2013-09-13 22:51:32 [iNFO] [sTDOUT]

2013-09-13 22:51:32 [iNFO] [sTDOUT] java.lang.NullPointerException

2013-09-13 22:51:32 [iNFO] [sTDOUT] at terramagna.utils.PlayerStatsUtil.onEntityJoinWorld(PlayerStatsUtil.java:27)

2013-09-13 22:51:32 [iNFO] [sTDOUT] at net.minecraftforge.event.ASMEventHandler_5_PlayerStatsUtil_onEntityJoinWorld_EntityJoinWorldEvent.invoke(.dynamic)

2013-09-13 22:51:32 [iNFO] [sTDOUT] at net.minecraftforge.event.ASMEventHandler.invoke(ASMEventHandler.java:39)

2013-09-13 22:51:32 [iNFO] [sTDOUT] at net.minecraftforge.event.EventBus.post(EventBus.java:108)

2013-09-13 22:51:32 [iNFO] [sTDOUT] at net.minecraft.world.World.spawnEntityInWorld(World.java:1572)

2013-09-13 22:51:32 [iNFO] [sTDOUT] at net.minecraft.server.management.ServerConfigurationManager.playerLoggedIn(ServerConfigurationManager.java:267)

2013-09-13 22:51:32 [iNFO] [sTDOUT] at net.minecraft.server.management.ServerConfigurationManager.initializeConnectionToPlayer(ServerConfigurationManager.java:136)

2013-09-13 22:51:32 [iNFO] [sTDOUT] at net.minecraft.server.integrated.IntegratedServerListenThread.networkTick(IntegratedServerListenThread.java:97)

2013-09-13 22:51:32 [iNFO] [sTDOUT] at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:689)

2013-09-13 22:51:32 [iNFO] [sTDOUT] at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:585)

2013-09-13 22:51:32 [iNFO] [sTDOUT] at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:129)

2013-09-13 22:51:32 [iNFO] [sTDOUT] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:482)

2013-09-13 22:51:32 [iNFO] [sTDOUT] at net.minecraft.server.ThreadMinecraftServer.run(ThreadMinecraftServer.java:16)

 

 

 

 

http://pastebin.com/yzFYunLL

[Lycanus Darkbinder]

Yes, those two code blocks are essentially the same. Some people prefer to not cast from one class to the other so pick whichever fits your code style.

 

As for the newest crash, you should check if the world is null before trying to use it. It's possible that the world field in EntityJoinWorldEvent() hasn't been set before your override gets called.

 

Also, try using event.entity.worldObj and see if that is null.

[Mazetar]

TLH:

Set a breakpoint at the crash line and see what's null during runtime?

[coolAlias]

Try using this in your EntityJoinWorldEvent instead:

if (event.entity instanceof EntityPlayer) {
  event.entity.getEntityData().setInteger("gold", 1000);
  // test to see if it worked:
  System.out.println("Player's gold: " + event.entity.getEntityData().getInteger("gold"));
}

'getEntityData()' returns the NBT Tag Compound associated with the entity, be it player or whatever. Then you can set the gold directly like that if you want.

 

You don't need to create all those other variables in your code, such as 'theNBT'. Just use the ones provided by the parameters.

[Lycanus Darkbinder]

Try using this in your EntityJoinWorldEvent instead:

if (event.entity instanceof EntityPlayer) {
  event.entity.getEntityData().setInteger("gold", 1000);
  // test to see if it worked:
  System.out.println("Player's gold: " + event.entity.getEntityData().getInteger("gold"));
}

'getEntityData()' returns the NBT Tag Compound associated with the entity, be it player or whatever. Then you can set the gold directly like that if you want.

 

You don't need to create all those other variables in your code, such as 'theNBT'. Just use the ones provided by the parameters.

 

The OP is using that event. I think the problem is that those objects have not been set yet when he / she is trying to access them.

 

It's similar to how you can't access worldObj in the constructor of a TileEntity because it does not get set until after the constructor.

[TLHPoE]

Ok, just rewrote my code so that it returns if anything is null.

 

http://pastebin.com/ZdN6knXV

 

 

Only problem now is that the NBT tag gets reset on death or when the player leaves the world and rejoins.

[coolAlias]

Try using this in your EntityJoinWorldEvent instead:

if (event.entity instanceof EntityPlayer) {
  event.entity.getEntityData().setInteger("gold", 1000);
  // test to see if it worked:
  System.out.println("Player's gold: " + event.entity.getEntityData().getInteger("gold"));
}

'getEntityData()' returns the NBT Tag Compound associated with the entity, be it player or whatever. Then you can set the gold directly like that if you want.

 

You don't need to create all those other variables in your code, such as 'theNBT'. Just use the ones provided by the parameters.

 

The OP is using that event. I think the problem is that those objects have not been set yet when he / she is trying to access them.

 

It's similar to how you can't access worldObj in the constructor of a TileEntity because it does not get set until after the constructor.

All of those fields should already be initialized in EntityJoinWorldEvent. I use it all the time to set IExtendedEntityProperty data specifically because these same objects are available for use, whereas, as you've pointed out, are NOT available in a constructor or using the EntityConstructingEvent.

 

@OP: I'd suggest taking a look at my tutorial on using IExtendedEntityProperties - there you will find a better way to add gold as well as get it to persist across player death and such. http://www.minecraftforum.net/topic/1952901-eventhandler-and-iextendedentityproperties/#entry24051513

[TLHPoE]

coolAlias: I got the idea of doing this from your tutorial, but I just want to use this way.