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+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+## [Unreleased]
+
+Nothing.
+
+## [3.1.0] - 2021-02-13
+
+Adds static methods for extracting information from ULIDs.
+
+### Added 
+
+- Added `CHANGELOG.md`
+- Added static method `Ulid.getInstant(String)`
+- Added static method `Ulid.getTime(String)`
+- Added static method `Ulid.getRandom(String)`
+
+### Changed
+
+- Updated `README.md`
+- Updated test cases
+
+## [3.0.1] - 2021-01-30
+
+### Changed
+
+- Renamed subpackage `creator` to `factory`
+
+## [3.0.0] - 2021-01-30
+
+This version breaks compatibility. It is a rewrite from scratch.
+
+Now the `uuid-creator` can generate two types of ULID: default (non-monotonic) and monotonic. Until version 2.3.3 this library only generated monotonic ULIDs.
+
+### Added
+
+- Added class `Ulid`
+- Added abstract class `UlidFactory`
+- Added class `DefaultUlidFactory`
+- Added class `MonotonicUlidFactory`
+- Added functional interface `RandomGenerator`
+- Added class `DefaultRandomGenerator`
+- Added static method `UlidCreator.getUlid(): Ulid`
+- Added static method `UlidCreator.getUlid(long): Ulid`
+- Added static method `UlidCreator.getMonotonicUlid(): Ulid`
+- Added static method `UlidCreator.getMonotonicUlid(long): Ulid`
+- Added static method `UlidCreator.getDefaultFactory(): UlidFactory`
+- Added static method `UlidCreator.getMonotonicFactory(): UlidFactory`
+
+### Changed
+
+- Rewrited `ulid-creator`
+- Rewrited all `README.md`
+- Rewrited all test cases
+
+### Removed
+
+- Removed class `UlidStruct`, replaced by `Ulid`
+- Removed class `UlidUtil`, use`Ulid` instead
+- Removed class `UlidConverter`, use `Ulid` instead
+- Removed class `UlidValidator`, use`Ulid` instead
+- Removed class `UlidSpecCreator`, replaced by `UlidFactory`
+- Removed class `InvalidUlidException`, replaced by `IllegalArgumentException`
+- Removed interface `RandomStrategy`, replaced by `RandomGenerator`
+- Removed class `DefaultRandomStrategy`, replaced by `DefaultRandomGenerator`
+- Removed class `OtherRandomStrategy``
+- Removed interface `TimestampStrategy`
+- Removed class `DefaultTimestampStrategy`
+- Removed class `FixedTimestampStrategy`
+- Removed static method `UlidCreator.fromString(String): UUID`
+- Removed static method `UlidCreator.toString(UUID): String`
+- Removed static method `UlidCreator.getUlid(): UUID`
+- Removed static method `UlidCreator.getUlid4(): UUID`
+- Removed static method `UlidCreator.getUlidString(): String`
+- Removed static method `UlidCreator.getUlidString4(): String`
+- Removed static method `UlidCreator.getUlidSpecCreator(): UlidSpecCreator`
+
+## [2.3.3] - 2020-11-16
+
+Optimization and housekeeping.
+
+### Added
+
+- Added test cases
+
+### Changed
+
+- Optimized `UlidSpecCreator`
+- Updated `README.md`
+
+### Removed
+
+- Removed unused code
+
+## [2.3.2] - 2020-11-09
+
+Only Optimization.
+
+### Changed
+
+- Optimized `UlidValidator`
+
+## [2.3.1] - 2020-11-08
+
+Added static methods for extracting Unix time.
+
+### Added
+
+- Added static method `UlidUtil.extractUnixMilliseconds(UUID)`
+- Added static method `UlidUtil.extractUnixMilliseconds(String)`
+
+### Changed
+
+- Moved UUID v4 generation to `UlidStruct`
+- Updated test cases
+
+## [2.3.0] - 2020-11-08
+
+Now it can generate UUIDs and ULIDs compatible with RFC-4122 UUID v4.
+
+### Added
+
+- Added static method `UlidCreator.getUlid4()`
+- Added static method `UlidCreator.getUlidString4()`
+- Added method `UlidSpecCreator.create4()`
+- Added method `UlidSpecCreator.createString4()`
+
+### Changed
+
+- Updated `README.md`
+- Updated test cases
+
+## [2.2.0] - 2020-11-08
+
+Now the generation of ULID in canonical string format is 2.5x faster than before.
+
+### Added
+
+- Added `UlidStruct` for internal use
+- Added test cases
+
+### Changed
+
+- Optimized `UlidSpecCreator` by using `UlidStruct`
+- Optimized `UlidConverter` by using `UlidStruct`
+- Optimized `UlidValidator`
+- Updated `README.md`
+- Updated javadoc
+
+## [2.1.0] - 2020-10-17
+
+Removed the overrun exception because it is extremely unlikely to occur
+
+### Changed
+
+- Updated `README.md`
+- Updated test cases
+- Updated javadoc
+
+### Removed
+
+- Removed `UlidCreatorException`, used in overruns
+
+## [2.0.0] - 2020-07-04
+
+This version breaks compatibility.
+
+### Added
+
+- Added `RandomStrategy`
+- Added `DefaultRandomStrategy`
+- Added `OtherRandomStrategy`
+- Added test cases
+
+### Changed
+
+- Changed `UlidCreator`
+- Renamed `UlidBasedGuidCreator` to `UlidSpecCreator`
+- Changed JDK version from 11 to 8 for compatibility with Java 8
+- Optimized `UlidConverter.fromString(String)`
+- Optimized `UlidConverter.toString(UUID)`
+- Optimized `UlidValidator.isValid(String)`
+- Updated `README.md`
+- Updated `pom.xml`
+- Updated test cases
+- Updated javadoc
+
+## [1.1.0] - 2020-04-18
+
+### Changed
+
+- Renamed `GuidCreator` to `UlidBasedGuidCreator`
+- Changed the overrun exception to be thrown when 2^80 requests occurs within the same msec
+- Updated `README.md`
+- Updated `pom.xml`
+- Updated test cases
+
+### Removed
+
+- Removed unused code
+
+## [1.0.0] - 2020-02-23
+
+Project created as an alternative Java implementation of [ULID spec](https://github.com/ulid/spec).
+
+### Added
+
+- Added `UlidCreator`
+- Added `GuidCreator`
+- Added `TimestampStrategy`
+- Added `DefaultTimestampStrategy`
+- Added `FixedTimestampStrategy`
+- Added `XorshiftRandom`
+- Added `Xorshift128PlusRandom`
+- Added `Base32Util`
+- Added `ByteUtil`
+- Added `FingerprintUtil`
+- Added `NetworkData`
+- Added `UlidUtil`
+- Added `UlidCreatorException`
+- Added `README.md`
+- Added `pom.xml`
+- Added `LICENSE`
+- Added test cases
+
+[unreleased]: https://github.com/f4b6a3/ulid-creator/compare/ulid-creator-3.1.0...HEAD
+[3.1.0]: https://github.com/f4b6a3/ulid-creator/compare/ulid-creator-3.0.1...ulid-creator-3.1.0
+[3.0.1]: https://github.com/f4b6a3/ulid-creator/compare/ulid-creator-3.0.0...ulid-creator-3.0.1
+[3.0.0]: https://github.com/f4b6a3/ulid-creator/compare/ulid-creator-2.3.3...ulid-creator-3.0.0
+[2.3.3]: https://github.com/f4b6a3/ulid-creator/compare/ulid-creator-2.3.2...ulid-creator-2.3.3
+[2.3.2]: https://github.com/f4b6a3/ulid-creator/compare/ulid-creator-2.3.1...ulid-creator-2.3.2
+[2.3.1]: https://github.com/f4b6a3/ulid-creator/compare/ulid-creator-2.3.0...ulid-creator-2.3.1
+[2.3.0]: https://github.com/f4b6a3/ulid-creator/compare/ulid-creator-2.2.0...ulid-creator-2.3.0
+[2.2.0]: https://github.com/f4b6a3/ulid-creator/compare/ulid-creator-2.1.0...ulid-creator-2.2.0
+[2.1.0]: https://github.com/f4b6a3/ulid-creator/compare/ulid-creator-2.0.0...ulid-creator-2.1.0
+[1.1.0]: https://github.com/f4b6a3/ulid-creator/compare/ulid-creator-1.1.0...ulid-creator-2.0.0
+[2.0.0]: https://github.com/f4b6a3/ulid-creator/compare/ulid-creator-1.1.0...ulid-creator-2.0.0
+[1.1.0]: https://github.com/f4b6a3/ulid-creator/compare/ulid-creator-1.0.0...ulid-creator-1.1.0
+[1.0.0]: https://github.com/f4b6a3/ulid-creator/releases/tag/ulid-creator-1.0.0