com.github.f4b6a3.uuid.nodeid

Class SystemNodeIdentifierStrategy

java.lang.Object

com.github.f4b6a3.uuid.nodeid.SystemNodeIdentifierStrategy

All Implemented Interfaces:

NodeIdentifierStrategy

public class SystemNodeIdentifierStrategy
extends Object
implements NodeIdentifierStrategy

Field Summary

Fields

Modifier and Type	Field and Description
protected static MessageDigest	md
protected long	nodeIdentifier
protected Random	random

Constructor Summary

Constructors

Constructor and Description
SystemNodeIdentifierStrategy()

Method Summary

Modifier and Type	Method and Description
protected String	getHostName()
protected String	getJavaVirtualMachine()
protected String	getNetworkInterface()
long	getNodeIdentifier() Get a node identifier generated from system information.
protected String	getOperatingSystem()
protected String	getRandomHexadecimal()
protected long	getSystemNodeIdentifier() getNodeIdentifier()

Methods inherited from class java.lang.Object

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

Field Detail

nodeIdentifier

protected long nodeIdentifier

random

protected Random random

md

protected static MessageDigest md

Constructor Detail

SystemNodeIdentifierStrategy

public SystemNodeIdentifierStrategy()

Method Detail

getNodeIdentifier

public long getNodeIdentifier()

Get a node identifier generated from system information. It uses these information to generate the node identifier: hostname, IP, MAC, operating system and JVM. These information are concatenated and passed to a message digest. It returns the last six bytes of the resulting hash. ### RFC-4122 - 4.5. Node IDs that Do Not Identify the Host (4) In addition, items such as the computer's name and the name of the operating system, while not strictly speaking random, will help differentiate the results from those obtained by other systems. (5) The exact algorithm to generate a node ID using these data is system specific, because both the data available and the functions to obtain them are often very system specific. A generic approach, however, is to accumulate as many sources as possible into a buffer, use a message digest such as MD5 [4] or SHA-1 [8], take an arbitrary 6 bytes from the hash value, and set the multicast bit as described above.

Specified by:

getNodeIdentifier in interface NodeIdentifierStrategy

Returns:

a node identifier

getSystemNodeIdentifier

protected long getSystemNodeIdentifier()

getNodeIdentifier()

Returns:

a system id number

getHostName

protected String getHostName()

getOperatingSystem

protected String getOperatingSystem()

getJavaVirtualMachine

protected String getJavaVirtualMachine()

getNetworkInterface

protected String getNetworkInterface()

getRandomHexadecimal

protected String getRandomHexadecimal()