I wanna get a list of dimensions. So I tried DimensionManager.getStaticDimensionIDs(), but it doesn't work. It throws "java.lang.NullPointerException"

And I tried another way that from diesieben07，but it still can't work and my eclipse tell me that "Type mismatch: cannot convert from IntStream to int[]". 

 

Edited July 17, 20187 yr by Taskkill

Post your code.

1 minute ago, Animefan8888 said:

Post your code.

package TCr.Dark.items;

import java.util.stream.Stream;

import TCr.Dark.Dark;
import net.minecraft.client.resources.I18n;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.init.Biomes;
import net.minecraft.init.Blocks;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.nbt.NBTTagCompound;
import net.minecraft.util.ActionResult;
import net.minecraft.util.EnumHand;
import net.minecraft.util.math.BlockPos;
import net.minecraft.util.text.TextComponentString;
import net.minecraft.world.DimensionType;
import net.minecraft.world.World;
import net.minecraftforge.common.DimensionManager;

public class DimensionWand extends Item {

	public DimensionWand() {
		this.setUnlocalizedName("DimensionWand");
		this.setRegistryName("dimension_wand");
		this.setCreativeTab(Dark.tab);
		this.setMaxDamage(20);
	}
	
	@Override
	public ActionResult<ItemStack> onItemRightClick(World worldIn, EntityPlayer playerIn, EnumHand handIn) {
		if(!worldIn.isRemote) {
			NBTTagCompound nbt = playerIn.getHeldItem(handIn).getTagCompound();
			int[] dimensions = Stream.of(DimensionType.values()).flatMapToInt(t -> Stream.of(DimensionManager.getDimensions(t))).distinct();
			int max = dimensions.length;
			if(playerIn.isSneaking()) {
				playerIn.changeDimension(nbt.getInteger("dimension"));
			} else {
				int k = 0;
				k++;
				if(k > max) k = 0;
				nbt.setInteger("dimension", dimensions[k]);
				playerIn.sendMessage(new TextComponentString(I18n.format("dimensionWand.dim")+dimensions[k]));
			}
		}
		return super.onItemRightClick(worldIn, playerIn, handIn);
	}
	
}

 

1 minute ago, Taskkill said:

 

And the crash for this code.

Just now, Animefan8888 said:

And the crash for this code.

It didn't crash, just throw this.

[23:19:24] [Server thread/FATAL]: Error executing task
java.util.concurrent.ExecutionException: java.lang.NullPointerException
	at java.util.concurrent.FutureTask.report(Unknown Source) ~[?:1.8.0_151]
	at java.util.concurrent.FutureTask.get(Unknown Source) ~[?:1.8.0_151]
	at net.minecraft.util.Util.runTask(Util.java:54) [Util.class:?]
	at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:796) [MinecraftServer.class:?]
	at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:741) [MinecraftServer.class:?]
	at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:192) [IntegratedServer.class:?]
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:590) [MinecraftServer.class:?]
	at java.lang.Thread.run(Unknown Source) [?:1.8.0_151]
Caused by: java.lang.NullPointerException
	at TCr.Dark.items.DimensionWand.onItemRightClick(DimensionWand.java:34) ~[DimensionWand.class:?]
	at net.minecraft.item.ItemStack.useItemRightClick(ItemStack.java:234) ~[ItemStack.class:?]
	at net.minecraft.server.management.PlayerInteractionManager.processRightClick(PlayerInteractionManager.java:384) ~[PlayerInteractionManager.class:?]
	at net.minecraft.network.NetHandlerPlayServer.processTryUseItem(NetHandlerPlayServer.java:794) ~[NetHandlerPlayServer.class:?]
	at net.minecraft.network.play.client.CPacketPlayerTryUseItem.processPacket(CPacketPlayerTryUseItem.java:43) ~[CPacketPlayerTryUseItem.class:?]
	at net.minecraft.network.play.client.CPacketPlayerTryUseItem.processPacket(CPacketPlayerTryUseItem.java:9) ~[CPacketPlayerTryUseItem.class:?]
	at net.minecraft.network.PacketThreadUtil$1.run(PacketThreadUtil.java:21) ~[PacketThreadUtil$1.class:?]
	at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) ~[?:1.8.0_151]
	at java.util.concurrent.FutureTask.run(Unknown Source) ~[?:1.8.0_151]
	at net.minecraft.util.Util.runTask(Util.java:53) ~[Util.class:?]
	... 5 more

 

14 minutes ago, Taskkill said:

DimensionWand.java:34

Which line is line 34?

1 minute ago, Draco18s said:

Which line is line 34?

Integer[] dimensions = DimensionManager.getStaticDimensionIDs();

3 minutes ago, diesieben07 said:

So the posted code was incomplete? Also: https://git.io/fNs8k.

 

DimensionManager has a convenient method called getRegisteredDimensions. Use it.

Thanks, but how can I turn this Map into int array. 

3 minutes ago, diesieben07 said:

This should do it. Haven't written Java in a while.

DimensionManager.getRegisteredDimensions().values().stream().flatMap(Collection::stream).mapToInt(Integer::intValue).toArray()

Thanks!

9 minutes ago, Taskkill said:

Thanks, but how can I turn this Map into int array. 

 

Although diesieben07s flatmap approach should work, it is good to understand what you're doing. This is really just basic Java. You have a map and it has keys of DimensionType and values of IntSortedSet. If you think about what that means, there is a set of ints (i.e. dimension ids) for each dimension type.

 

So the logical way to turn this into an array of ints is to iterate through the map (i.e. loop through each DimensionType) and then take the value int set and iterate through that, putting each element into your array.

 

Edited July 17, 20187 yr by jabelar

17 minutes ago, jabelar said:

 

Although diesieben07s flatmap approach should work, it is good to understand what you're doing. This is really just basic Java. You have a map and it has keys of DimensionType and values of IntSortedSet. If you think about what that means, there is a set of ints (i.e. dimension ids) for each dimension type.

 

So the logical way to turn this into an array of ints is to iterate through the map (i.e. loop through each DimensionType) and then take the value int set and iterate through that, putting each element into your array.

 

I know that is basic java, but I just know a little about Map, so... But thanks!

20 minutes ago, diesieben07 said:

A big part of functional programming is declarative programming: Stating what result you want, not how to get there. And since functional programming is all the rage, so obviously everyone should use it all the time. Just saying. ? Seriously though, it's 2018. Nobody should be manually iterating arrays, unless you are writing like... a video encoder.

I agree except ... people need to understand what is going on underneath. It is great if there is already a method for flattening collections, but I don't think it really helps understand the underlying construction of the data. The question posted indicated he didn't really even know what a map is.

Edited July 17, 20187 yr by jabelar