CodecUtil

CodecUtil is an abstract utility class providing static Codec / MapCodec constants and helper methods for serializing game objects to JSON, NBT, or configuration files.

Built-in Codecs

Field	Type	Description
ITEM	Codec<Item>	Serializes items by registry ID string; air or invalid IDs return an error
BLOCK	Codec<Block>	Serializes blocks by registry ID string
ENTITY	Codec<EntityType<?>>	Entity type codec with registry existence validation
CHAR	Codec<Character>	Single character codec
NUMBER_PROVIDER	Codec<NumberProvider>	Supports standard NumberProvider structures and plain integers (auto-expanded to ConstantValue)
BLOCK_STATE_MAP_CODEC	MapCodec<BlockState>	Identifies the block via the "block" field and carries property values in the "state" field

Block State Codec

// Build a property codec for a specific BlockState
MapCodec<BlockState> codec = CodecUtil.blockStatePropertiesCodec(state);

// Append a property field to an existing MapCodec
MapCodec<BlockState> extended = CodecUtil.appendBlockStatePropertyCodec(
    base, supplier, name, property, defValue
);

Enum Codecs

Method	Description
enumCodecInInt(Class<T>)	Encode/decode by ordinal integer
enumCodecInLowerName(Class<T>)	Encode/decode by lowercase name string

Codec<MyEnum> intCodec = CodecUtil.enumCodecInInt(MyEnum.class);
Codec<MyEnum> nameCodec = CodecUtil.enumCodecInLowerName(MyEnum.class);

Optional Codec

// Optional codec with an explicit isPresent boolean field
Codec<Optional<T>> codec = CodecUtil.createOptionalCodec(innerCodec);

Collection Codecs

// LinkedList codec
Codec<LinkedList<T>> listCodec = CodecUtil.linkedListOf(innerCodec);

// Deque codec
Codec<Deque<T>> dequeCodec = CodecUtil.dequeOf(innerCodec, factoryFunction);

Recipe-Related

// Create a size-limited NonNullList<Ingredient> codec
Codec<NonNullList<Ingredient>> ingredients = CodecUtil.createIngredientListCodec(
    "ingredients", 9, recipeType
);

Single-Entry Map Conversion

// Convert Codec<Map<K,V>> to Codec<T>, suitable for {"key": value} format
Codec<T> byMap = CodecUtil.byMap(mapCodec, keyGetter, valueGetter, factory);

Usage Examples

// Full block state codec
MapCodec<BlockState> blockStateMapCodec = CodecUtil.BLOCK_STATE_MAP_CODEC;

// Enum codec by name
Codec<MyEnum> enumCodec = CodecUtil.enumCodecInLowerName(MyEnum.class);

// NumberProvider supports both numeric and standard structure formats
Codec<NumberProvider> npCodec = CodecUtil.NUMBER_PROVIDER;