Ghost-chu
commented
3 years ago Closed Ghost-chu closed 3 years ago
Ghost-chu
commented
3 years ago 
Jakllp
commented
3 years ago Can you provide info on what the player did and what pet this occurred with?
Ghost-chu
commented
3 years ago Player get offline, so as far as I know, player just random disconnect and this is only what I found in console.
Ghost-chu
commented
3 years ago okay reproduce: summon your pet, then killed it
Ghost-chu
commented
3 years ago AttributeSupplier possibly null. (AttributeSupplier =AttributeProvider)
So I guess something wrong in there:
protected void replaceCraftAttributes() {
//TODO check this
Field craftAttributesField = ReflectionUtil.getField(LivingEntity.class, "craftAttributes");
CraftAttributeMap craftAttributes = new CraftAttributeMap(this.getAttributes());
ReflectionUtil.setFinalFieldValue(craftAttributesField, this, craftAttributes);
} public static boolean setFinalFieldValue(@NonNull Field field, Object target, Object value) {
try {
field.setAccessible(true);
Field modifiersField = Field.class.getDeclaredField("modifiers");
modifiersField.setAccessible(true);
modifiersField.setInt(field, field.getModifiers() & ~Modifier.FINAL);
field.set(target, value);
return true;
} catch (Throwable ignored) {
}
return false;
}This method exceptions has been hidden, and I guess this is why I didn't see any error in console.
Jakllp
commented
3 years ago Good find, just edited it to print the StackTrace -> throws an error
Jakllp
commented
3 years ago Tested this some more - Seems to be a java 16 related.
How was this tested: Ran a 1.16.5 server with MyPet3.11-SNAPSHOT-B1642 on Java16: Same Error Ran the same server on Java 11: No error
Ghost-chu
commented
3 years ago Make a quick search on our local Minecraft forum, try this out: (Java 9+):
public static void grantAccess(Class<?> clazz){
Field theUnsafe = null;
try {
theUnsafe = Unsafe.class.getDeclaredField("theUnsafe");
theUnsafe.setAccessible(true);
Unsafe unsafe = (Unsafe) theUnsafe.get(null);
Field module = Class.class.getDeclaredField("module");
long offset = unsafe.objectFieldOffset(module);
unsafe.putObject(clazz, offset, Object.class.getModule());
} catch (NoSuchFieldException | IllegalAccessException e) {
e.printStackTrace();
}
}like this:
public static boolean setFinalFieldValue(String fieldName, Object target, Object value) {
try {
Field field = getField(target.getClass(), fieldName);
if (field != null) {
FooBar.grantAccess(this);
field.setAccessible(true);
Field modifiersField = Field.class.getDeclaredField("modifiers");
modifiersField.setAccessible(true);
modifiersField.setInt(field, field.getModifiers() & ~Modifier.FINAL);
field.set(target, value);
return true;
}
} catch (Throwable ignored) {
}
return false;
}I didn't test it yet, trying to fix some maven issue.
Jakllp
commented
3 years ago Done in https://github.com/Jakllp/MyPet/commit/474496fd8ba5bf12738f0626552002dd7252acfb
If you wanna build the plugin yourself you can look at the BuildGuide
Jakllp
commented
3 years ago (Note: We are just not doing whatever it was doing to the modifier anymore...)
minecraft8997
commented
2 years ago Hello! I'm writing a plugin that adds custom entity and I get the same exception message:
java.lang.NullPointerException: Cannot invoke "net.minecraft.world.entity.ai.attributes.AttributeProvider.a(java.util.function.Consumer, net.minecraft.world.entity.ai.attributes.AttributeBase)" because "this.d" is null
at net.minecraft.world.entity.ai.attributes.AttributeMap.lambda$getInstance$1(AttributeMap.java:50) ~[?:?]
at java.util.HashMap.computeIfAbsent(HashMap.java:1219) ~[?:?]
at net.minecraft.world.entity.ai.attributes.AttributeMap.getInstance(AttributeMap.java:49) ~[?:?]
...How did you solve it?
Jakllp
commented
2 years ago See: https://github.com/Jakllp/MyPet/commit/474496fd8ba5bf12738f0626552002dd7252acfb
I had to change setFinalFieldValue() which is used to replace the craftAttributes-Field here
Thing is: I only needed to change it bc you don't need to modify the "modifiers" field in java 16+ anymore. You should check if you're replacing the craftAttributes first
minecraft8997
commented
2 years ago Thanks for the answer!
I can't replace it because the plugin crashes at doing super(type, world).
I'm registering the entity by changing the value of an existing private static final field in the EntityTypes class (and it doesn't work without removing the final field, I'm on MC 1.18.1 and Java 17).
Jakllp
commented
2 years ago In case you're talking about net.minecraft.world.entity.EntityType: Take a look at how this plugin registers it's EntityTypes here
In case you're talking about org.bukkit.entity.EntityType: That's an enum. Can't change that.
minecraft8997
commented
2 years ago Is it possible to register custom entity (by replacing an existing one) without registering custom net.minecraft.world.entity.EntityTypes?
Jakllp
commented
2 years ago maybe, idk