Manipulating NBT

NBT

NBT is a binary tag format used to save information about items, block states and entities in Minecraft. Each one of these can be saved and read from a root NBT compound (CompoundTag), which is essentially a map with different tags inside of it. The supported tags to save information are:

• CompoundTag (a map of many other tags)
• ListTag (a list of different tags of the same type)
• StringTag (a simple tag containing a String)
• ByteTag, ShortTag, IntTag, LongTag, DoubleTag and FloatTag (simple tag types containing a byte, short, integer, long, double or float value, respectively)
• IntArrayTag and ByteArrayTag (tags containing an array of integers or bytes, respectively)

In Glowstone, these tags are implemented in the net.glowstone.util.nbt package and extend the Tag class. There is no NBT API in the Bukkit API or its forks, so you must add the Glowstone server as a dependency directly to manipulate NBT tags. Note that we do not ensure backwards-compatibility when using Glowstone as a dependency.

Entities

To save or load an Entity from an NBT Compound, you can use the following methods:

Saving (writing)

// Create an empty compound tag to save the entity to
CompoundTag tag = new CompoundTag();
// Write the entity data in the compound tag
EntityStorage.save(entity, tag);

Reading

// Create a compound tag and write some data in it
CompoundTag tag = new CompoundTag();
tag.putString("foo", "bar");
// ...
// Load the data from the tag to the entity
EntityStorage.load(entity, tag);