Help with Custom Entity 1.7.2

Hi, I need some help understanding bukkit 1.7.2 custom entities. I go ahead and make the classes that need to be made.

CustomEntityType.class

Code:java

 
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.List;
 
import net.minecraft.server.v1_7_R1.BiomeBase;
import net.minecraft.server.v1_7_R1.BiomeMeta;
import net.minecraft.server.v1_7_R1.EntityInsentient;
import net.minecraft.server.v1_7_R1.EntityTypes;
import net.minecraft.server.v1_7_R1.EntityZombie;
 
import org.bukkit.entity.EntityType;
 
public enum CustomEntityType
{
 
ZOMBIE("Zombie", 54, EntityType.ZOMBIE, EntityZombie.class, CustomEntityZombie.class);
 
private String name;
private int id;
private EntityType entityType;
private Class<? extends EntityInsentient> nmsClass;
private Class<? extends EntityInsentient> customClass;
 
private CustomEntityType(String name, int id, EntityType entityType, Class<? extends EntityInsentient> nmsClass, Class<? extends EntityInsentient> customClass)
{
this.name = name;
this.id = id;
this.entityType = entityType;
this.nmsClass = nmsClass;
this.customClass = customClass;
}
 
public String getName()
{
return this.name;
}
 
public int getID()
{
return this.id;
}
 
public EntityType getEntityType()
{
return this.entityType;
}
 
public Class<? extends EntityInsentient> getNMSClass()
{
return this.nmsClass;
}
 
public Class<? extends EntityInsentient> getCustomClass()
{
return this.customClass;
}
 
public static void registerEntities()
{
for (CustomEntityType entity : values())
{
try
{
Method a = EntityTypes.class.getDeclaredMethod("a", new Class<?>[]
{Class.class, String.class, int.class});
a.setAccessible(true);
a.invoke(null, entity.getCustomClass(), entity.getName(), entity.getID());
} catch (Exception e)
{
e.printStackTrace();
}
}
 
BiomeBase[] biomes;
try
{
biomes = (BiomeBase[]) getPrivateStatic(BiomeBase.class, "biomes");
} catch (Exception exc)
{
System.out.println("Biome loading messed up!");
return;
}
for (BiomeBase biomeBase : biomes)
{
if (biomeBase == null)
break;
 
for (String field : new String[]
{"as", "at", "au", "av"})
try
{
Field list = BiomeBase.class.getDeclaredField(field);
list.setAccessible(true);
@SuppressWarnings("unchecked")
List<BiomeMeta> mobList = (List<BiomeMeta>) list.get(biomeBase);
 
for (BiomeMeta meta : mobList)
for (CustomEntityType entity : values())
if (entity.getNMSClass().equals(meta.b))
meta.b = entity.getCustomClass();
} catch (Exception e)
{
e.printStackTrace();
}
}
}
 
private static Object getPrivateStatic(Class<BiomeBase> clazz, String f) throws NoSuchFieldException, SecurityException, IllegalArgumentException, IllegalAccessException
{
Field field = clazz.getDeclaredField(f);
field.setAccessible(true);
return field.get(null);
}
}
 

CustomEntityZombie.class

Code:java

 
import net.minecraft.server.v1_7_R1.EntityZombie;
import net.minecraft.server.v1_7_R1.World;
 
public class CustomEntityZombie extends EntityZombie
{
public CustomEntityZombie(World world)
{
super(world);
}
}
 

Then I run the plugin and get error

Code:

[14:50:57 WARN]: java.lang.reflect.InvocationTargetException
.........
[14:50:57 WARN]: Caused by: java.lang.IllegalArgumentException: ID is already re
gistered: Zombie
[14:50:57 WARN]:        at net.minecraft.server.v1_7_R1.EntityTypes.a(SourceFile
:30)

So how can ID be already registered??

Thanks!

 

I have the same problem. Have you figured out a solution yet? When I try to register it as a different String ID or int ID the client crashes.

 

it's already registered because minecraft registers their zombie class with the same id and name, to overwrite their registration do this:

Code:java

public static void registerEntities() {
for (CustomEntityType entity : values()) {
try {
Class<?> en = EntityTypes.class;
Field c = en.getDeclaredField("c");
c.setAccessible(true);
Field d = en.getDeclaredField("d");
d.setAccessible(true);
Field e = en.getDeclaredField("e");
e.setAccessible(true);
Field f = en.getDeclaredField("f");
f.setAccessible(true);
Field g = en.getDeclaredField("g");
g.setAccessible(true);
((Map) c.get(null)).put(entity.getName(), entity.getCustomClass());
((Map) d.get(null)).put(entity.getCustomClass(), entity.getName());
((Map) e.get(null)).put(entity.getID(), entity.getCustomClass());
((Map) f.get(null)).put(entity.getCustomClass(), entity.getID());
} catch (Exception e) {
e.printStackTrace();
}
}
for (BiomeBase biomeBase : BiomeBase.n()) {
if (biomeBase == null) {
break;
}
 
for (String field : new String[] { "as", "at", "au", "av" }) {
try {
Field list = BiomeBase.class.getDeclaredField(field);
list.setAccessible(true);
List<BiomeMeta> mobList = (List<BiomeMeta>) list.get(biomeBase);
 
for (BiomeMeta meta : mobList) {
for (CustomEntityType entity : values()) {
if (entity.getNMSClass().equals(meta.b)) {
meta.b = entity.getCustomClass();
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
}

 

EcMiner
But what if I don't want to change ALL entities to my special subclass, but I just want to create some special entities. If I use the first section of code to register the class and I use craftWorld.getHandler().addEntity(entity, SpawnReason.CUSTOM); then will it spawn the entity correctly? I don't want to change all entities to my special class, just a few specific ones.

 

If you created a custom zombie, it won't naturally spawn as your custom zombie, but when you use like a zombie monster egg, your custom zombie will spawn, if you use .addEntity() you can do new EntityZombie(....) it will spawn a normal zombie but if you do new CustomZombe(....) it will spawn your custom zombie

 

See the code snippet I posted here. I believe it's the forum post you got your CustomEntityTypes class from but I revised the code for 1.7.2. Minecraft added a check to ensure an entity wasn't registered twice with the same ID, but it can be easily bypassed with reflection.

There is also a reply on the page I linked to that provides a solution for allowing normal mobs to spawn when custom.

 

EcMiner TeeePeee
Thank you so much!! I have been stuck on this for multiple days and I finally figured out, thanks to your help, what I was doing wrong! When I attempted to manually write the id's, names, and classes into the maps in EntityTypes, I used the fields b, c, d, e, and f instead of c, d, e, f, and g. Thank you so much! I can continue to code now!

 

I recommend skipping "e", since that might make zombie eggs spawn your custom zombie instead of regular zombies. Correct me if I'm wrong.