Missing type arguments for generic class in Java?-CodePudding

I don't understand how to format generic types into this code:

import net.minecraft.client.renderer.entity.EntityRendererManager;
import net.minecraft.client.renderer.entity.SpiderRenderer;
import net.minecraft.entity.monster.SpiderEntity;
import net.minecraft.util.ResourceLocation;
import vazkii.quark.content.client.module.VariantAnimalTexturesModule;
import vazkii.quark.content.client.module.VariantAnimalTexturesModule.VariantTextureType;

public class VariantSpiderRenderer<T> extends SpiderRenderer<T> {

    public VariantSpiderRenderer(EntityRendererManager renderManagerIn) {
        super(renderManagerIn);
    }
    
    @Override
    public ResourceLocation getEntityTexture(SpiderEntity entity) {
        return VariantAnimalTexturesModule.getTextureOrShiny(entity, VariantTextureType.SPIDER, VariantAnimalTexturesModule.enableSpider);
    }
    
}

This is the error I get:

public class VariantSpiderRenderer extends SpiderRenderer {
                                           ^
      missing type arguments for generic class SpiderRenderer<T>
      where T is a type-variable:
        T extends SpiderEntity declared in class SpiderRenderer
    error: warnings found and -Werror specified
    warnings found and -Werror specified

I've been googling trying to figure out how to fix it but I don't understand.

Is this the code you asked for in the comment?

    package net.minecraft.client.renderer.entity;

import net.minecraft.client.renderer.entity.layers.SpiderEyesLayer;
import net.minecraft.client.renderer.entity.model.SpiderModel;
import net.minecraft.entity.monster.SpiderEntity;
import net.minecraft.util.ResourceLocation;
import net.minecraftforge.api.distmarker.Dist;
import net.minecraftforge.api.distmarker.OnlyIn;

@OnlyIn(Dist.CLIENT)
public class SpiderRenderer<T extends SpiderEntity> extends MobRenderer<T, SpiderModel<T>> {
   private static final ResourceLocation SPIDER_TEXTURES = new ResourceLocation("textures/entity/spider/spider.png");

   public SpiderRenderer(EntityRendererManager renderManagerIn) {
      super(renderManagerIn, new SpiderModel<>(), 0.8F);
      this.addLayer(new SpiderEyesLayer<>(this));
   }

   protected float getDeathMaxRotation(T entityLivingBaseIn) {
      return 180.0F;
   }

   /**
    * Returns the location of an entity's texture.
    */
   public ResourceLocation getEntityTexture(T entity) {
      return SPIDER_TEXTURES;
   }
}

CodePudding user response：

Your subclass is a generic type but bound to be of type SpiderEntity

public class SpiderRenderer<T extends SpiderEntity>

Your subclass is a generic type with no bounds:

public class VariantSpiderRenderer<T> extends SpiderRenderer<T>

Which means that you are trying to make it so you can create a VariantSpiderRenderer of some type - like VariantSpiderRenderer<String> - that is not compatible with the base class, which is required to be a SpiderRenderer of some type T that is at least a SpiderEntity.

To fix this, the derived class must respect and specify those bounds as well:

public class VariantSpiderRenderer<T extends SpiderEntity> extends SpiderRenderer<T>