I'm looking to create a mod item (class name "ExampleItem") that launches flaming pigs when the player right clicks. It's functionality would be similar to ender pearls, which spawn an entity (the ender pearl) with a velocity in the player's look direction.

So, I figured I would use the EnderPearlItem.class as a template, then modify the appropriate code to spawn a PigEntity rather than an EnderPearl entity. However, I'm less familiar with the process for spawning entities in the world with the latest version of forge.

Could anybody point me to an example of someone at least spawning an entity at player position with an item right click? Here is my code so far in ExampleItem.java:

 

import net.minecraft.entity.item.EnderPearlEntity;
import net.minecraft.entity.passive.PigEntity;
import net.minecraft.entity.player.PlayerEntity;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.stats.Stats;
import net.minecraft.util.ActionResult;
import net.minecraft.util.Hand;
import net.minecraft.util.SoundCategory;
import net.minecraft.util.SoundEvents;
import net.minecraft.world.World;

public class ExampleItem extends Item {
   public ExampleItem(Item.Properties p_i48501_1_) {
      super(p_i48501_1_);
   }
   
   public ActionResult<ItemStack> use(World p_77659_1_, PlayerEntity p_77659_2_, Hand p_77659_3_) {
      ItemStack itemstack = p_77659_2_.getItemInHand(p_77659_3_);
      p_77659_1_.playSound((PlayerEntity)null, p_77659_2_.getX(), p_77659_2_.getY(), p_77659_2_.getZ(), SoundEvents.ENDER_PEARL_THROW, SoundCategory.NEUTRAL, 0.5F, 0.4F / (random.nextFloat() * 0.4F + 0.8F));
      p_77659_2_.getCooldowns().addCooldown(this, 20);
      if (!p_77659_1_.isClientSide) {
    	  
    	  PigEntity flyingPig = new PigEntity(null, p_77659_1_);
    	  flyingPig.setPos(p_77659_2_.getX(), p_77659_2_.getY(), p_77659_2_.getZ());
    	  p_77659_1_.addFreshEntity(flyingPig); 
    	  flyingPig.setSecondsOnFire(10);

      }

      p_77659_2_.awardStat(Stats.ITEM_USED.get(this));
      if (!p_77659_2_.abilities.instabuild) {
         itemstack.shrink(1);
      }

      return ActionResult.sidedSuccess(itemstack, p_77659_1_.isClientSide());
   }
}

And here is the main error I'm getting: 


 

[17:25:34] [Server thread/FATAL] [minecraft/ThreadTaskExecutor]: Error executing task on Server
java.lang.NullPointerException: Cannot invoke "net.minecraft.entity.EntityType.getDimensions()" because "p_i48580_1_" is null
	at net.minecraft.entity.Entity.<init>(Entity.java:203) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.entity.LivingEntity.<init>(LivingEntity.java:205) ~[forge:?] {re:classloading}
	at net.minecraft.entity.MobEntity.<init>(MobEntity.java:108) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.entity.CreatureEntity.<init>(CreatureEntity.java:13) ~[forge:?] {re:classloading}
	at net.minecraft.entity.AgeableEntity.<init>(AgeableEntity.java:21) ~[forge:?] {re:classloading}
	at net.minecraft.entity.passive.AnimalEntity.<init>(AnimalEntity.java:37) ~[forge:?] {re:classloading}
	at net.minecraft.entity.passive.PigEntity.<init>(PigEntity.java:59) ~[forge:?] {re:classloading}
	at com.dcox.modwroman.common.items.ExampleItem.use(ExampleItem.java:27) ~[?:?] {re:classloading}
	at net.minecraft.item.ItemStack.use(ItemStack.java:217) ~[forge:?] {re:classloading,xf:fml:forge:filled_map.4,xf:fml:forge:itemstack}
	at net.minecraft.server.management.PlayerInteractionManager.useItem(PlayerInteractionManager.java:287) ~[forge:?] {re:classloading}
	at net.minecraft.network.play.ServerPlayNetHandler.handleUseItem(ServerPlayNetHandler.java:982) ~[forge:?] {re:classloading}
	at net.minecraft.network.play.client.CPlayerTryUseItemPacket.handle(CPlayerTryUseItemPacket.java:28) ~[forge:?] {re:classloading}
	at net.minecraft.network.play.client.CPlayerTryUseItemPacket.handle(CPlayerTryUseItemPacket.java:9) ~[forge:?] {re:classloading}
	at net.minecraft.network.PacketThreadUtil.lambda$ensureRunningOnSameThread$0(PacketThreadUtil.java:19) ~[forge:?] {re:classloading}
	at net.minecraft.util.concurrent.TickDelayedTask.run(TickDelayedTask.java:17) ~[forge:?] {re:classloading}
	at net.minecraft.util.concurrent.ThreadTaskExecutor.doRunTask(ThreadTaskExecutor.java:136) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.util.concurrent.RecursiveEventLoop.doRunTask(RecursiveEventLoop.java:22) ~[forge:?] {re:classloading}
	at net.minecraft.server.MinecraftServer.doRunTask(MinecraftServer.java:734) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.server.MinecraftServer.doRunTask(MinecraftServer.java:159) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.util.concurrent.ThreadTaskExecutor.pollTask(ThreadTaskExecutor.java:109) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.server.MinecraftServer.pollTaskInternal(MinecraftServer.java:717) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.server.MinecraftServer.pollTask(MinecraftServer.java:711) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.util.concurrent.ThreadTaskExecutor.runAllTasks(ThreadTaskExecutor.java:97) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.server.MinecraftServer.waitUntilNextTick(MinecraftServer.java:696) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:646) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:232) ~[forge:?] {re:classloading,pl:accesstransformer:B}
	at java.lang.Thread.run(Thread.java:832) [?:?] {}

 

Quote

new PigEntity(null

Why are you passing null as the entity type?