com.github.f4b6a3.uuid.factory.abst

Class AbstractNameBasedUuidCreator

java.lang.Object

com.github.f4b6a3.uuid.factory.abst.AbstractUuidCreator

com.github.f4b6a3.uuid.factory.abst.AbstractNameBasedUuidCreator

Direct Known Subclasses:

NameBasedMd5UuidCreator, NameBasedSha1UuidCreator

public abstract class AbstractNameBasedUuidCreator
extends AbstractUuidCreator

Factory that creates name-based UUIDs.

Field Summary

Fields

Modifier and Type	Field and Description
protected MessageDigest	md
protected static String	MESSAGE_DIGEST_MD5
protected static String	MESSAGE_DIGEST_SHA1
protected UUID	namespace

Fields inherited from class com.github.f4b6a3.uuid.factory.abst.AbstractUuidCreator

version, versionBits

Constructor Summary

Constructors

Constructor and Description
AbstractNameBasedUuidCreator(UuidVersion version, String messageDigest) This constructor receives the name of a message digest.

Method Summary

Modifier and Type	Method and Description
UUID	create(byte[] name) Returns a name-based UUID without name space.
UUID	create(String name) Returns a name-based UUID without name space.
UUID	create(String namespace, byte[] name) Returns a name-based UUID with a name space and a name.
UUID	create(String namespace, String name) Returns a name-based UUID with a name space and a name.
UUID	create(UUID namespace, byte[] name) Returns a name-based UUID with a name space and a name. ### RFC-4122 - 4.3.
UUID	create(UuidNamespace namespace, String name) Returns a name-based UUID with a name space and a name.
UUID	create(UUID namespace, String name) Returns a name-based UUID with a name space and a name.
<T extends AbstractNameBasedUuidCreator> T	withNamespace(String namespace) Sets a fixed name space with in a fluent way.
<T extends AbstractNameBasedUuidCreator> T	withNamespace(UUID namespace) Sets a fixed name space with in a fluent way.
<T extends AbstractNameBasedUuidCreator> T	withNamespace(UuidNamespace namespace) Sets a fixed name space with in a fluent way.

Methods inherited from class com.github.f4b6a3.uuid.factory.abst.AbstractUuidCreator

getVariantBits, getVersion, getVersionBits, setVariantBits, setVersionBits

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

namespace

protected UUID namespace

md

protected MessageDigest md

MESSAGE_DIGEST_MD5

protected static final String MESSAGE_DIGEST_MD5

See Also:

Constant Field Values

MESSAGE_DIGEST_SHA1

protected static final String MESSAGE_DIGEST_SHA1

See Also:

Constant Field Values

Constructor Detail

AbstractNameBasedUuidCreator

public AbstractNameBasedUuidCreator(UuidVersion version,
                                    String messageDigest)

This constructor receives the name of a message digest. In this implementation it's possible to use ANY message digest that Java supports, but only MD5 and SHA-1 are used by the the RFC-4122. Someone can implement a non-standard name-based factory that uses a better message digest, by extending this abstract class. A subclass that uses the algorithm SHA-256 is provided by this library.

Parameters:

version - the version number

messageDigest - a message digest

Method Detail

withNamespace

public <T extends AbstractNameBasedUuidCreator> T withNamespace(UuidNamespace namespace)

Sets a fixed name space with in a fluent way.

Type Parameters:

T - the type parameter

Parameters:

namespace - a namespace enum

Returns:

AbstractNameBasedUuidCreator

withNamespace

public <T extends AbstractNameBasedUuidCreator> T withNamespace(UUID namespace)

Sets a fixed name space with in a fluent way.

Type Parameters:

T - the type parameter

Parameters:

namespace - a namespace UUID

Returns:

AbstractNameBasedUuidCreator

withNamespace

public <T extends AbstractNameBasedUuidCreator> T withNamespace(String namespace)

Sets a fixed name space with in a fluent way. The name space string is converted to name space UUID.

Type Parameters:

T - the type parameter

Parameters:

namespace - a name space string

Returns:

AbstractNameBasedUuidCreator

create

public UUID create(String name)

Returns a name-based UUID without name space. create(UUID, byte[])

Parameters:

name - a name string

Returns:

a name-based UUID

create

public UUID create(byte[] name)

Returns a name-based UUID without name space. create(UUID, byte[])

Parameters:

name - a byte array of the name in UTF8

Returns:

a name-based UUID

create

public UUID create(String namespace,
                   String name)

Returns a name-based UUID with a name space and a name. The name space string is converted to name space UUID. create(UUID, byte[])

Parameters:

namespace - a name space string

name - a name string

Returns:

a name-based UUID

create

public UUID create(String namespace,
                   byte[] name)

Returns a name-based UUID with a name space and a name. The name space string is converted to name space UUID. create(UUID, byte[])

Parameters:

namespace - a name space string

name - a byte array of the name in UTF8

Returns:

a name-based UUID

create

public UUID create(UUID namespace,
                   String name)

Returns a name-based UUID with a name space and a name. create(UUID, byte[])

Parameters:

namespace - a name space UUID

name - a byte array of the name in UTF8

Returns:

a name-based UUID

create

public UUID create(UuidNamespace namespace,
                   String name)

Returns a name-based UUID with a name space and a name. UuidNamespace. create(UUID, byte[])

Parameters:

namespace - a name space enumeration

name - a byte array of the name in UTF8

Returns:

a name-based UUID

create

public UUID create(UUID namespace,
                   byte[] name)

Returns a name-based UUID with a name space and a name. ### RFC-4122 - 4.3. Algorithm for Creating a Name-Based UUID (1) Allocate a UUID to use as a "name space ID" for all UUIDs generated from names in that name space; see Appendix C for some pre-defined values. (2) Choose either MD5 [4] or SHA-1 [8] as the hash algorithm; If backward compatibility is not an issue, SHA-1 is preferred. (3) Convert the name to a canonical sequence of octets (as defined by the standards or conventions of its name space); put the name space ID in network byte order. (4) Compute the hash of the name space ID concatenated with the name. (5) Set octets zero through 3 of the time_low field to octets zero through 3 of the hash. (6) Set octets zero and one of the time_mid field to octets 4 and 5 of the hash. (7) Set octets zero and one of the time_hi_and_version field to octets 6 and 7 of the hash. (8) Set the four most significant bits (bits 12 through 15) of the time_hi_and_version field to the appropriate 4-bit version number from Section 4.1.3. (9) Set the clock_seq_hi_and_reserved field to octet 8 of the hash. (10) Set the two most significant bits (bits 6 and 7) of the clock_seq_hi_and_reserved to zero and one, respectively. (11) Set the clock_seq_low field to octet 9 of the hash. (12) Set octets zero through five of the node field to octets 10 through 15 of the hash. (13) Convert the resulting UUID to local byte order.

Parameters:

namespace - a name space UUID

name - a byte array of the name in UTF8

Returns:

a name-based UUID