com.github.f4b6a3.uuid.util

Class SystemDataUtil

java.lang.Object

com.github.f4b6a3.uuid.util.SystemDataUtil

public class SystemDataUtil
extends Object

Field Summary

Fields

Modifier and Type	Field and Description
protected static MessageDigest	md

Method Summary

Modifier and Type	Method and Description
static int	getAvailableProcessors()
static String	getJavaVirtualMachine() Returns a string of the JVM details.
static long	getMaxMemory()
static String	getNetwork() Returns a string of the network details.
static NetworkData	getNetworkData() Returns a NetworkData.
static List<NetworkData>	getNetworkDataList() Returns a list of NetworkData.
static String	getOperatingSystem() Returns a string of the OS details.
static String	getResources()
static String	getSystemDataHash(String salt) Returns a hash string generated from all the system data: OS + JVM + network details + system resources + SALT.
static long	getSystemId(String salt) Returns a system hash ID generated from all the system details concatenated: OS + JVM + network details + system resources + SALT.

Methods inherited from class java.lang.Object

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

Field Detail

md

protected static MessageDigest md

Method Detail

getSystemId

public static long getSystemId(String salt)

Returns a system hash ID generated from all the system details concatenated: OS + JVM + network details + system resources + SALT. Get a system identifier generated from system information. It uses these information to generate the node identifier: operating system, java virtual machine, network details, system resources and an optional salt. 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 (1) This section describes how to generate a version 1 UUID if an IEEE 802 address is not available, or its use is not desired. (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.

Parameters:

salt - an optional arbitrary string to change the final hash

Returns:

a system identifier

getSystemDataHash

public static String getSystemDataHash(String salt)

Returns a hash string generated from all the system data: OS + JVM + network details + system resources + SALT.

Parameters:

salt - an optional arbitrary string to change the final hash

Returns:

a string

getOperatingSystem

public static String getOperatingSystem()

Returns a string of the OS details.

Returns:

a string

getJavaVirtualMachine

public static String getJavaVirtualMachine()

Returns a string of the JVM details.

Returns:

a string

getResources

public static String getResources()

getAvailableProcessors

public static int getAvailableProcessors()

getMaxMemory

public static long getMaxMemory()

getNetwork

public static String getNetwork()

Returns a string of the network details. It's done in three two steps: 1. it tries to find the network data associated with the host name; 2. otherwise, it iterates throw all interfaces to return the first one that is up and running.

Returns:

a string

getNetworkData

public static NetworkData getNetworkData()

Returns a NetworkData. This method returns the network data associated to the host name.

Returns:

a NetworkData

getNetworkDataList

public static List<NetworkData> getNetworkDataList()

Returns a list of NetworkData. This method iterates over all the network interfaces to return those that are up and running. NOTE: it may be VERY EXPENSIVE on Windows systems, because it creates a lot of virtual network interfaces.

Returns:

a list of NetworkData