org.apache.kafka.common

Class Uuid

java.lang.Object

org.apache.kafka.common.Uuid

All Implemented Interfaces:

Comparable<Uuid>

public class Uuid
extends Object
implements Comparable<Uuid>

This class defines an immutable universally unique identifier (UUID). It represents a 128-bit value. More specifically, the random UUIDs generated by this class are variant 2 (Leach-Salz) version 4 UUIDs. This is the same type of UUID as the ones generated by java.util.UUID. The toString() method prints using the base64 string encoding. Likewise, the fromString method expects a base64 string encoding.

Field Summary

Fields

Modifier and Type	Field and Description
static Uuid	METADATA_TOPIC_ID A UUID for the metadata topic in KRaft mode.
static Uuid	ZERO_UUID A UUID that represents a null or empty UUID.

Constructor Summary

Constructors

Constructor and Description
Uuid(long mostSigBits, long leastSigBits) Constructs a 128-bit type 4 UUID where the first long represents the most significant 64 bits and the second long represents the least significant 64 bits.

Method Summary

Modifier and Type	Method and Description
int	compareTo(Uuid other)
boolean	equals(Object obj) Returns true iff obj is another Uuid represented by the same two long values.
static Uuid	fromString(String str) Creates a UUID based on a base64 string encoding used in the toString() method.
long	getLeastSignificantBits() Returns the least significant bits of the UUID's 128 value.
long	getMostSignificantBits() Returns the most significant bits of the UUID's 128 value.
int	hashCode() Returns a hash code for this UUID
static Uuid	randomUuid() Static factory to retrieve a type 4 (pseudo randomly generated) UUID.
String	toString() Returns a base64 string encoding of the UUID.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

METADATA_TOPIC_ID

public static final Uuid METADATA_TOPIC_ID

A UUID for the metadata topic in KRaft mode. Will never be returned by the randomUuid method.

ZERO_UUID

public static final Uuid ZERO_UUID

A UUID that represents a null or empty UUID. Will never be returned by the randomUuid method.

Constructor Detail

Uuid

public Uuid(long mostSigBits,
            long leastSigBits)

Constructs a 128-bit type 4 UUID where the first long represents the most significant 64 bits and the second long represents the least significant 64 bits.

Method Detail

randomUuid

public static Uuid randomUuid()

Static factory to retrieve a type 4 (pseudo randomly generated) UUID. This will not generate a UUID equal to 0, 1, or one whose string representation starts with a dash ("-")

getMostSignificantBits

public long getMostSignificantBits()

Returns the most significant bits of the UUID's 128 value.

getLeastSignificantBits

public long getLeastSignificantBits()

Returns the least significant bits of the UUID's 128 value.

equals

public boolean equals(Object obj)

Returns true iff obj is another Uuid represented by the same two long values.

Overrides:

equals in class Object

hashCode

public int hashCode()

Returns a hash code for this UUID

Overrides:

hashCode in class Object

toString

public String toString()

Returns a base64 string encoding of the UUID.

Overrides:

toString in class Object

fromString

public static Uuid fromString(String str)

Creates a UUID based on a base64 string encoding used in the toString() method.

compareTo

public int compareTo(Uuid other)

Specified by:

compareTo in interface Comparable<Uuid>