任务 ':compileJava' 执行失败

Question

我正在尝试制作一个 Minecraft mod，它应该能让蝙蝠掉落生鸡肉。 Minecraft 确实启动并实际打开，但是当它进入 compileJava 阶段时，控制台中会显示错误。我对Java知之甚少，所以不知道如何总结

我的问题是这些错误消息是什么意思，我该如何更正它们？

我问过我的一些同事关于这个问题，但他们也不知道。


//NOTE TO SELF: Learn to indent.

package net.mcreator.trevcorp_meat_paste;

import net.minecraftforge.fml.relauncher.SideOnly;
import net.minecraftforge.fml.relauncher.Side;
import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
import net.minecraftforge.fml.common.eventhandler.EventPriority;
import net.minecraftforge.fml.common.event.FMLInitializationEvent;
import net.minecraftforge.common.MinecraftForge;
import net.minecraftforge.client.event.RenderGameOverlayEvent;

import net.minecraft.world.World;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.client.Minecraft;
import net.minecraft.entity.passive.EntityBat;

public static class GUIRenderEventClass
{@SubscribeEvent
public void playerKilledBat(livingDropsEvent event)
   {
      if(event.entityLiving instanceof EntityBat)
      {
         event.drops.clear();
         itemStack itemStackToDrop = new itemStack(items.chicken, 1);
         event.drops.add(new EntityItem(event.entity.worldObj, event.entity.posX, 
              event.entity.posY, event.entity.posZ, itemStackToDrop));

      }
}
}

Minecraft 确实打开了，但是当它进入编译Java 阶段时，它会在控制台中显示以下错误消息：

C:\Users\USER\MCreatorWorkspaces\trevcorp_meat_paste\build\sources\main\java\net\mcreator\trevcorp_meat_paste\MCreatorBatMeat.java:16: error: class GUIRenderEventClass is public, should be declared in a file named GUIRenderEventClass.java
public static class GUIRenderEventClass
              ^
C:\Users\USER\MCreatorWorkspaces\trevcorp_meat_paste\build\sources\main\java\net\mcreator\trevcorp_meat_paste\MCreatorBatMeat.java:18: error: cannot find symbol
public void playerKilledBat(livingDropsEvent event)
                            ^
  symbol:   class livingDropsEvent
  location: class GUIRenderEventClass
C:\Users\USER\MCreatorWorkspaces\trevcorp_meat_paste\build\sources\main\java\net\mcreator\trevcorp_meat_paste\MCreatorBatMeat.java:24: error: cannot find symbol
         itemStack itemStackToDrop = new itemStack(items.chicken, 1);
         ^
  symbol:   class itemStack
  location: class GUIRenderEventClass
C:\Users\USER\MCreatorWorkspaces\trevcorp_meat_paste\build\sources\main\java\net\mcreator\trevcorp_meat_paste\MCreatorBatMeat.java:24: error: cannot find symbol
         itemStack itemStackToDrop = new itemStack(items.chicken, 1);
                                         ^
  symbol:   class itemStack
  location: class GUIRenderEventClass
C:\Users\USER\MCreatorWorkspaces\trevcorp_meat_paste\build\sources\main\java\net\mcreator\trevcorp_meat_paste\MCreatorBatMeat.java:24: error: cannot find symbol
         itemStack itemStackToDrop = new itemStack(items.chicken, 1);
                                                   ^
  symbol:   variable items
  location: class GUIRenderEventClass
C:\Users\USER\MCreatorWorkspaces\trevcorp_meat_paste\build\sources\main\java\net\mcreator\trevcorp_meat_paste\MCreatorBatMeat.java:25: error: cannot find symbol
         event.drops.add(new EntityItem(event.entity.worldObj, event.entity.posX, 
                             ^
  symbol:   class EntityItem
  location: class GUIRenderEventClass
Note: Some input files use or override a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
Note: Some input files use unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
6 errors

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':compileJava'.
> Compilation failed; see the compiler error output for details.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 8s

Answer 1

第一条错误信息，

class GUIRenderEventClass is public, should be declared in a file named GUIRenderEventClass.java public static class GUIRenderEventClass

表示您的 Java 源位于一个文件中，该文件的名称与源代码中的 Java class 名称不匹配。 Java 源文件名和文件中 class 的 Java class 名称必须匹配。 Java 编译器就是这样找到东西的。

您还有一些相同类型的错误，例如：

 C:\Users\USER\MCreatorWorkspaces\trevcorp_meat_paste\build\sources\main\java\net\mcreator\trevcorp_meat_paste\MCreatorBatMeat.java:18: error: cannot find symbol public void playerKilledBat(livingDropsEvent event)

这意味着当 Java 编译器处理源代码时，它发现了一个它不知道的符号或类型或某种名称。这是一个错误，表示在 Java 编译器搜索时找不到指定的符号或类型或名称。

发生这种情况有多种原因。

最常见的情况是包含符号或类型或名称的文件缺少 import 指令。这是涉及类型的 "symbol not found" 错误的最可能原因。看起来你有几个 "symbol not found" 的案例，这可能是由于缺少 import 文件，例如：

class livingDropsEvent是找不到的符号
class itemStack是找不到的符号
class EntityItem是找不到的符号

也没有找到变量items。我认为它可能也是 import 文件中某处的全局变量。

查看 Jabelar 的 Minecraft Forge 改装教程上的这篇文章，Minecraft Forge 1.7.2/1.7.10 Changing Drops of Vanilla Entities as well as Minecraft Modding: Event Handling，了解有关这些符号的一些详细信息。

另请查看 mincraftforge 论坛中的示例代码，https://www.minecraftforge.net/forum/topic/28747-how-to-add-a-drop-to-a-vanilla-mob-1710/ 其中包含这组 import 指令：

   import net.minecraft.block.Block;
   import net.minecraft.block.material.Material;
   import net.minecraft.creativetab.CreativeTabs;
   import net.minecraft.entity.boss.EntityWither;
   import net.minecraft.entity.item.EntityItem;
   import net.minecraft.init.Items;
   import net.minecraft.item.Item;
   import net.minecraft.item.ItemStack;
   import net.minecraft.util.WeightedRandomChestContent;
   import net.minecraftforge.common.ChestGenHooks;
   import net.minecraftforge.common.util.EnumHelper;
   import net.minecraftforge.event.entity.living.LivingDropsEvent;

最后你有一些警告：

Note: Some input files use or override a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
Note: Some input files use unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.

这些警告可能重要也可能不重要。如果它们来自您正在使用的某个图书馆的某个来源，您可能无法解决这些问题。无论这些警告如何，您的应用程序都可以运行。

任务 ':compileJava' 执行失败

Execution failed for task ':compileJava'

java

minecraft

minecraft-forge