Java Implementation for Minecraft Java Edition NBT Format.

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This library is Java implementation of the NBT protocol for Minecraft Java Edition. This library provides functionality for handling Named Binary Tag (NBT) data, which is a data interchange format used by Minecraft.

The NBT specification defines 13 different types of tags:

Tag class	ID	Payload
End	0	0 bytes
Byte	1	1 byte / 8 bits, signed
Short	2	2 bytes / 16 bits, signed, big endian
Int	3	4 bytes / 32 bits, signed, big endian
Long	4	8 bytes / 64 bits, signed, big endian
Float	5	4 bytes / 32 bits, signed, big endian, IEEE 754-2008, binary32
Double	6	8 bytes / 64 bits, signed, big endian, IEEE 754-2008, binary64
ByteArray	7	A signed integer (4 bytes) size, then the bytes comprising an array of length size.
String	8	An unsigned short (2 bytes) payload length, then a UTF-8 string resembled by length bytes.
List	9	A byte denoting the tag ID of the list's contents, followed by the list's length as a signed integer (4 bytes), then length number of payloads that correspond to the given tag ID.
Compound	10	Fully formed tags, followed by a TAG_End.
IntArray	11	A signed integer size, then size number of TAG_Int's payloads.
LongArray	12	A signed integer size, then size number of TAG_Long's payloads.

• Every valid NBT structure starts with a compound tag, known as the root compound. All other elements within the NBT structure are nested within this root compound.

• The End tag serves to mark the end of either a compound or an empty list tag within the NBT structure.

Features

• Comprehensive support for all NBT tags
• Lightweight and intuitive
• Supports new changes introduced in 1.20.2 version of Minecraft
• Supports SNBT serialization and deserialization, including boolean types
• Supports compression
• Easily expandable visitor API

SNBT Format

Library supports SNBT (Stringified NBT) format defined by Mojang, utilized to represent NBT tags as human-readable strings. This is widely used for NBT user input.

Example of SNBT format:

{Fire:10,Leashed:1b,FallFlying:0b,Rotation:[60F,15F],Leash:{X:12,Y:15,Z:1}}

Importing

Gradle

repositories {
    maven {
        name = "machinemcRepositoryReleases"
        url = uri("https://repo.machinemc.org/releases")
    }
}

dependencies {
    implementation("org.machinemc:nbt-core:VERSION")

    // for the SNBT parser
    implementation("org.machinemc:nbt-parser:VERSION")
}

Maven

<repositories>
    <repository>
        <id>machinemc-repository-releases</id>
        <name>MachineMC Repository</name>
        <url>https://repo.machinemc.org/releases</url>
    </repository>
</repositories>

<dependencies>
    <dependency>
        <groupId>org.machinemc</groupId>
        <artifactId>nbt-core</artifactId>
        <version>VERSION</version>
    </dependency>

    <!-- for the SNBT parser -->
    <dependency>
        <groupId>org.machinemc</groupId>
        <artifactId>nbt-parser</artifactId>
        <version>VERSION</version>
    </dependency>
</dependencies>

Example usage

The following code snippet shows how to create NBTCompound:

NBTCompound compound = new NBTCompound();
compound.set("hello", "there");
compound.set("test", 10);
compound.set("thing", -5.2);
compound.set("ints", new int[]{1, 2, 3});

More examples can be found in the unit tests.

License

NBT is free software licensed under the MIT license.