kotlinx-uuid-core
This core module contains several helper methods for the Uuid class, like timestamp, variant, version.
Generating UUID5 using hash
kotlinx-uuid provides the ability to generate uuids by hashing names (Only SHA-1 is supported at the moment).
val appNamespace = Uuid.parse("my-app-uuid")
val agentId = Uuid.generateUuid(appNamespace, "agentId")The other alternative is to generate Uuid by hashing bytes (similar to java.util.UUID.nameUUIDFromBytes).
val uuid = Uuid.generateUUID(bytes)Note that unlike
java.util.UUID, kotlinx's generateUUID doesn't support MD5, so the blind migration from Java to kotlin-uud may lead to changing UUIDs.
UUID7 Draft
This library contains experimental support for UUIDv7 according to this draft IETF.
val unixTimestamp = 42 // 48 bit
val uuid = UUIDv7(unixTimestamp)
uuid.unixTimeStamp // 42Serializing (kotlinx.serialization)
There is also a binary serializers for Uuid. This additional serializer is useful for binary formats. Because they are not human-readable, and it's possible to reduce size.
val bytes = Protobuf.encodeToByteArray(BinarySerializer, uuid)This core module contains several helper methods for the kotlin.uuid.Uuid class, like timestamp, variant, version.
Generating UUID5 using hash
kotlinx-uuid provides the ability to generate uuids by hashing names (Only SHA-1 is supported at the moment).
val appNamespace = Uuid.parse("my-app-uuid")
val agentId = Uuid.generateUuid(appNamespace, "agentId")The other alternative is to generate Uuid by hashing bytes (similar to java.util.UUID.nameUUIDFromBytes).
val uuid = Uuid.generateUUID(bytes)Note that unlike
java.util.UUID, kotlinx's generateUUID doesn't support MD5, so the blind migration from Java to kotlin-uud may lead to changing UUIDs.
UUID7 Draft
This library contains experimental support for UUIDv7 according to this draft IETF.
val unixTimestamp = 42 // 48 bit
val uuid = UUIDv7(unixTimestamp)
uuid.unixTimeStamp // 42Serializing (kotlinx.serialization)
There is also a binary serializers for Uuid. This additional serializer is useful for binary formats. Because they are not human-readable, and it's possible to reduce size.
val bytes = Protobuf.encodeToByteArray(BinarySerializer, uuid)This core module contains several helper methods for the Uuid class, like timestamp, variant, version.
Generating UUID5 using hash
kotlinx-uuid provides the ability to generate uuids by hashing names (Only SHA-1 is supported at the moment).
val appNamespace = Uuid.parse("my-app-uuid")
val agentId = Uuid.generateUuid(appNamespace, "agentId")The other alternative is to generate Uuid by hashing bytes (similar to java.util.UUID.nameUUIDFromBytes).
val uuid = Uuid.generateUUID(bytes)Note that unlike
java.util.UUID, kotlinx's generateUUID doesn't support MD5, so the blind migration from Java to kotlin-uud may lead to changing UUIDs.
UUID7 Draft
This library contains experimental support for UUIDv7 according to this draft IETF.
val unixTimestamp = 42 // 48 bit
val uuid = UUIDv7(unixTimestamp)
uuid.unixTimeStamp // 42Serializing (kotlinx.serialization)
There is also a binary serializers for Uuid. This additional serializer is useful for binary formats. Because they are not human-readable, and it's possible to reduce size.
val bytes = Protobuf.encodeToByteArray(BinarySerializer, uuid)