java.lang.Object
- com.github.f4b6a3.ulid.Ulid

All Implemented Interfaces:

Serializable, Comparable<Ulid>
```
public final class Ulid
extends Object
implements Serializable, Comparable<Ulid>
```
A class that represents ULIDs.
ULID is a 128-bit value that has two components:
- Time component: a number of milliseconds since 1970-01-01 (Unix epoch).
- Random component: a sequence of 80 random bits generated by a secure random generator.
ULID has 128-bit compatibility with UUID. Like a UUID, a ULID can also be stored as a 16-byte array.
Instances of this class are immutable.
See Also:

ULID Specification, Serialized Form

Field Summary

Fields
Modifier and Type	Field	Description
`static Ulid`	`MAX`	A special ULID that has all 128 bits set to ONE.
`static Ulid`	`MIN`	A special ULID that has all 128 bits set to ZERO.
`static int`	`RANDOM_BYTES`	Number of bytes of the random component of a ULID.
`static int`	`RANDOM_CHARS`	Number of characters of the random component of a ULID.
`static int`	`TIME_BYTES`	Number of bytes of the time component of a ULID.
`static int`	`TIME_CHARS`	Number of characters of the time component of a ULID.
`static int`	`ULID_BYTES`	Number of bytes of a ULID.
`static int`	`ULID_CHARS`	Number of characters of a ULID.

Constructor Summary

Constructors
Constructor	Description
`Ulid(long time, byte[] random)`	Creates a new ULID.
`Ulid(long mostSignificantBits, long leastSignificantBits)`	Creates a new ULID.
`Ulid(Ulid ulid)`	Creates a new ULID.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`int`	`compareTo(Ulid that)`	Compares two ULIDs as unsigned 128-bit integers.
`boolean`	`equals(Object other)`	Checks if some other ULID is equal to this one.
`static Ulid`	`fast()`	Returns a fast new ULID.
`static Ulid`	`from(byte[] bytes)`	Converts a byte array into a ULID.
`static Ulid`	`from(String string)`	Converts a canonical string into a ULID.
`static Ulid`	`from(UUID uuid)`	Converts a UUID into a ULID.
`Instant`	`getInstant()`	Returns the instant of creation.
`static Instant`	`getInstant(String string)`	Returns the instant of creation.
`long`	`getLeastSignificantBits()`	Returns the least significant bits as a number.
`long`	`getMostSignificantBits()`	Returns the most significant bits as a number.
`byte[]`	`getRandom()`	Returns the random component as a byte array.
`static byte[]`	`getRandom(String string)`	Returns the random component as a byte array.
`long`	`getTime()`	Returns the time component as a number.
`static long`	`getTime(String string)`	Returns the time component as a number.
`int`	`hashCode()`	Returns a hash code value for the ULID.
`Ulid`	`increment()`	Returns a new ULID by incrementing the random component of the current ULID.
`static boolean`	`isValid(String string)`	Checks if the input string is valid.
`static Ulid`	`max(long time)`	Returns the maximum ULID for a given time.
`static Ulid`	`min(long time)`	Returns the minimum ULID for a given time.
`byte[]`	`toBytes()`	Convert the ULID into a byte array.
`String`	`toLowerCase()`	Converts the ULID into a canonical string in lower case.
`Ulid`	`toRfc4122()`	Converts the ULID into into another ULID that is compatible with UUIDv4.
`String`	`toString()`	Converts the ULID into a canonical string in upper case.
`UUID`	`toUuid()`	Convert the ULID into a UUID.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - ULID_CHARS
```
public static final int ULID_CHARS
```
    Number of characters of a ULID.
    
    See Also:
    
    Constant Field Values
  - TIME_CHARS
```
public static final int TIME_CHARS
```
    Number of characters of the time component of a ULID.
    
    See Also:
    
    Constant Field Values
  - RANDOM_CHARS
```
public static final int RANDOM_CHARS
```
    Number of characters of the random component of a ULID.
    
    See Also:
    
    Constant Field Values
  - ULID_BYTES
```
public static final int ULID_BYTES
```
    Number of bytes of a ULID.
    
    See Also:
    
    Constant Field Values
  - TIME_BYTES
```
public static final int TIME_BYTES
```
    Number of bytes of the time component of a ULID.
    
    See Also:
    
    Constant Field Values
  - RANDOM_BYTES
```
public static final int RANDOM_BYTES
```
    Number of bytes of the random component of a ULID.
    
    See Also:
    
    Constant Field Values
  - MIN
```
public static final Ulid MIN
```
    A special ULID that has all 128 bits set to ZERO.
  - MAX
```
public static final Ulid MAX
```
    A special ULID that has all 128 bits set to ONE.
- Constructor Detail
  - Ulid
```
public Ulid(Ulid ulid)
```
    Creates a new ULID.
    Useful to make copies of ULIDs.
    
    Parameters:
    
    ulid - a ULID
  - Ulid
```
public Ulid(long mostSignificantBits,
            long leastSignificantBits)
```
    Creates a new ULID.
    If you want to make a copy of a UUID, use from(UUID) instead.
    
    Parameters:
    
    mostSignificantBits - the first 8 bytes as a long value
    
    leastSignificantBits - the last 8 bytes as a long value
  - Ulid
```
public Ulid(long time,
            byte[] random)
```
    Creates a new ULID.
    Time parameter is the number of milliseconds since 1970-01-01 (Unix epoch). It must be a positive number not larger than 2^48-1.
    Random parameter must be an array of 10 bytes.
    
    Parameters:
    
    time - the the number of milliseconds since 1970-01-01
    
    random - an array of 10 bytes
    
    Throws:
    
    IllegalArgumentException - if time is negative or larger than 2^48-1
    
    IllegalArgumentException - if random is null or its length is not 10
- Method Detail
  - fast
```
public static Ulid fast()
```
    Returns a fast new ULID.
    This static method is a quick alternative to UlidCreator.getUlid().
    It employs ThreadLocalRandom which works very well, although not cryptographically strong. It can be useful, for example, for logging.
    Security-sensitive applications that require a cryptographically secure pseudo-random generator should use UlidCreator.getUlid().
    
    Returns:
    
    a ULID
    
    Since:
    
    5.1.0
  - min
```
public static Ulid min(long time)
```
    Returns the minimum ULID for a given time.
    The 48 bits of the time component are filled with the given time and the 80 bits of the random component are all set to ZERO.
    For example, the minimum ULID for 2022-02-22 22:22:22.222 is `new Ulid(0x017f2387460e0000L, 0x0000000000000000L)`, where `0x017f2387460e` is the timestamp in hexadecimal.
    It can be useful to find all records before or after a specific timestamp in a table without a `created_at` field.
    
    Parameters:
    
    time - the the number of milliseconds since 1970-01-01
    
    Returns:
    
    a ULID
    
    Since:
    
    5.2.0
  - max
```
public static Ulid max(long time)
```
    Returns the maximum ULID for a given time.
    The 48 bits of the time component are filled with the given time and the 80 bits or the random component are all set to ONE.
    For example, the maximum ULID for 2022-02-22 22:22:22.222 is `new Ulid(0x017f2387460effffL, 0xffffffffffffffffL)`, where `0x017f2387460e` is the timestamp in hexadecimal.
    It can be useful to find all records before or after a specific timestamp in a table without a `created_at` field.
    
    Parameters:
    
    time - the the number of milliseconds since 1970-01-01
    
    Returns:
    
    a ULID
    
    Since:
    
    5.2.0
  - from
```
public static Ulid from(UUID uuid)
```
    Converts a UUID into a ULID.
    
    Parameters:
    
    uuid - a UUID
    
    Returns:
    
    a ULID
  - from
```
public static Ulid from(byte[] bytes)
```
    Converts a byte array into a ULID.
    
    Parameters:
    
    bytes - an array of 16 bytes
    
    Returns:
    
    a ULID
    
    Throws:
    
    IllegalArgumentException - if bytes are null or its length is not 16
  - from
```
public static Ulid from(String string)
```
    Converts a canonical string into a ULID.
    The input string must be 26 characters long and must contain only characters from Crockford's base 32 alphabet.
    The first character of the input string must be between 0 and 7.
    
    Parameters:
    
    string - a canonical string
    
    Returns:
    
    a ULID
    
    Throws:
    
    IllegalArgumentException - if the input string is invalid
    
    See Also:
    
    Crockford's Base 32
  - toUuid
```
public UUID toUuid()
```
    Convert the ULID into a UUID.
    A ULID has 128-bit compatibility with a UUID.
    If you need a RFC-4122 UUIDv4 do this: Ulid.toRfc4122().toUuid().
    
    Returns:
    
    a UUID.
  - toBytes
```
public byte[] toBytes()
```
    Convert the ULID into a byte array.
    
    Returns:
    
    an byte array.
  - toString
```
public String toString()
```
    Converts the ULID into a canonical string in upper case.
    The output string is 26 characters long and contains only characters from Crockford's Base 32 alphabet.
    For lower case string, use the shorthand Ulid#toLowerCase(), instead of Ulid#toString()#toLowerCase().
    
    Overrides:
    
    toString in class Object
    
    Returns:
    
    a ULID string
    
    See Also:
    
    Crockford's Base 32
  - toLowerCase
```
public String toLowerCase()
```
    Converts the ULID into a canonical string in lower case.
    The output string is 26 characters long and contains only characters from Crockford's Base 32 alphabet.
    It is a shorthand at least twice as fast as Ulid.toString().toLowerCase().
    
    Returns:
    
    a string
    
    See Also:
    
    Crockford's Base 32
  - toRfc4122
```
public Ulid toRfc4122()
```
    Converts the ULID into into another ULID that is compatible with UUIDv4.
    The bytes of the returned ULID are compliant with the RFC-4122 version 4.
    If you need a RFC-4122 UUIDv4 do this: Ulid.toRfc4122().toUuid().
    Note: If you use this method, you can not get the original ULID, since it changes 6 bits of it to generate a UUIDv4.
    
    Returns:
    
    a ULID
    
    See Also:
    
    RFC-4122
  - getInstant
```
public Instant getInstant()
```
    Returns the instant of creation.
    The instant of creation is extracted from the time component.
    
    Returns:
    
    the Instant of creation
  - getInstant
```
public static Instant getInstant(String string)
```
    Returns the instant of creation.
    The instant of creation is extracted from the time component.
    
    Parameters:
    
    string - a canonical string
    
    Returns:
    
    the Instant of creation
    
    Throws:
    
    IllegalArgumentException - if the input string is invalid
  - getTime
```
public long getTime()
```
    Returns the time component as a number.
    The time component is a number between 0 and 2^48-1. It is equivalent to the count of milliseconds since 1970-01-01 (Unix epoch).
    
    Returns:
    
    a number of milliseconds
  - getTime
```
public static long getTime(String string)
```
    Returns the time component as a number.
    The time component is a number between 0 and 2^48-1. It is equivalent to the count of milliseconds since 1970-01-01 (Unix epoch).
    
    Parameters:
    
    string - a canonical string
    
    Returns:
    
    a number of milliseconds
    
    Throws:
    
    IllegalArgumentException - if the input string is invalid
  - getRandom
```
public byte[] getRandom()
```
    Returns the random component as a byte array.
    The random component is an array of 10 bytes (80 bits).
    
    Returns:
    
    a byte array
  - getRandom
```
public static byte[] getRandom(String string)
```
    Returns the random component as a byte array.
    The random component is an array of 10 bytes (80 bits).
    
    Parameters:
    
    string - a canonical string
    
    Returns:
    
    a byte array
    
    Throws:
    
    IllegalArgumentException - if the input string is invalid
  - getMostSignificantBits
```
public long getMostSignificantBits()
```
    Returns the most significant bits as a number.
    
    Returns:
    
    a number.
  - getLeastSignificantBits
```
public long getLeastSignificantBits()
```
    Returns the least significant bits as a number.
    
    Returns:
    
    a number.
  - increment
```
public Ulid increment()
```
    Returns a new ULID by incrementing the random component of the current ULID.
    Since the random component contains 80 bits:
    
    (1) This method can generate up to 1208925819614629174706176 (2^80) ULIDs per millisecond;
    (2) This method can generate monotonic increasing ULIDs 99.999999999999992% ((2^80 - 10^9) / (2^80)) of the time within a single millisecond interval, considering an unrealistic rate of 1,000,000,000 ULIDs per millisecond.
    
    Due to (1) and (2), it does not throw the error message recommended by the specification. When an overflow occurs in the random 80 bits, the time component is simply incremented to maintain monotonicity.
    Returns:
    
    a ULID
  - isValid
```
public static boolean isValid(String string)
```
    Checks if the input string is valid.
    The input string must be 26 characters long and must contain only characters from Crockford's base 32 alphabet.
    The first character of the input string must be between 0 and 7.
    
    Parameters:
    
    string - a canonical string
    
    Returns:
    
    true if the input string is valid
    
    See Also:
    
    Crockford's Base 32
  - hashCode
```
public int hashCode()
```
    Returns a hash code value for the ULID.
    
    Overrides:
    
    hashCode in class Object
  - equals
```
public boolean equals(Object other)
```
    Checks if some other ULID is equal to this one.
    
    Overrides:
    
    equals in class Object
  - compareTo
```
public int compareTo(Ulid that)
```
    Compares two ULIDs as unsigned 128-bit integers.
    The first of two ULIDs is greater than the second if the most significant byte in which they differ is greater for the first ULID.
    
    Specified by:
    
    compareTo in interface Comparable<Ulid>
    
    Parameters:
    
    that - a ULID to be compared with
    
    Returns:
    
    -1, 0 or 1 as this is less than, equal to, or greater than that

Class Ulid

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

ULID_CHARS

TIME_CHARS

RANDOM_CHARS

ULID_BYTES

TIME_BYTES

RANDOM_BYTES

MIN

MAX

Constructor Detail

Ulid

Ulid

Ulid

Method Detail

fast

min

max

from

from

from

toUuid

toBytes

toString

toLowerCase

toRfc4122

getInstant

getInstant

getTime

getTime

getRandom

getRandom

getMostSignificantBits

getLeastSignificantBits

increment

isValid

hashCode

equals

compareTo