I want my custom wagon entity to add an instance of EntityAnimal and add it to a field like an array or list for my custom entity and have the passive entity move while the wagon is moving. When getEntitiesWithinAABB is called, it's not returning any entities in the list, I am fairly new to entity processing. I am using similar code found in the method interactFirst of the EntityLeashKnot class. Here is the source code:

/**
* First layer of player interaction
*/
public boolean interactFirst(EntityPlayer playerEntity)
{
double minMaxAABB = 7.0D;

// Get list of all entities leashed by player
List leashedList = this.worldObj.getEntitiesWithinAABB(
EntityAnimal.class,
AxisAlignedBB.getBoundingBox((double) this.posX - minMaxAABB, (double) this.posY
- minMaxAABB, (double) this.posZ - minMaxAABB, (double) this.posX
- minMaxAABB, (double) this.posY + minMaxAABB, (double) this.posZ
+ minMaxAABB));

// if there are up to 2 entities leashed anchor them to the wagon
if (leashedList != null && leashedList.size() <= 2)
{
	System.out.println("Returned list of leashed entities on interaction with wagon entity");
	Iterator iterator = leashedList.iterator();

	while (iterator.hasNext())
	{
		EntityAnimal entity = (EntityAnimal) iterator.next();

		if (entity.getLeashed() && entity.getLeashedToEntity() == playerEntity)
		{
			// break leash from player
			entity.clearLeashed(true, true);

			// add entity to wagon
			this.entityHorses.add(entity);

			// DEBUG: to know the correct entities are referenced
			System.out.println(this.entityHorses.isEmpty());
		}
	}

}
return true;
}

You made a typo in your bounding box:

AxisAlignedBB.getBoundingBox((double) this.posX - minMaxAABB, (double) this.posY

- minMaxAABB, (double) this.posZ - minMaxAABB, (double) this.posX

- minMaxAABB, (double) this.posY + minMaxAABB, (double) this.posZ

+ minMaxAABB));

 

The second posX should be +minMaxAABB not -minMaxAABB.

 

Thank you so much, its working now.