com.eaio.uuid.UUIDGen Maven / Gradle / Ivy
/*
* UUIDGen.java
*
* Created on 09.08.2003.
*
* eaio: UUID - an implementation of the UUID specification
* Copyright (c) 2003-2013 Johann Burkard ([email protected]) http://eaio.com.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
* NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
* USE OR OTHER DEALINGS IN THE SOFTWARE.
*
*/
package com.eaio.uuid;
import static com.eaio.util.Resource.close;
import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.InetAddress;
import java.net.InterfaceAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.util.Enumeration;
import java.util.concurrent.atomic.AtomicLong;
import java.util.Random;
import com.eaio.util.lang.Hex;
/**
* This class contains methods to generate UUID fields. These methods have been
* refactored out of {@link com.eaio.uuid.UUID}.
*
* Starting with version 2, this implementation tries to obtain the MAC address
* of the network card. Under Microsoft Windows, the ifconfig
* command is used which may pop up a command window in Java Virtual Machines
* prior to 1.4 once this class is initialized. The command window is closed
* automatically.
*
* The MAC address code has been tested extensively in Microsoft Windows,
* Linux, Solaris 8, HP-UX 11, but should work in MacOS X and BSDs, too.
*
* If you use JDK 6 or later, the code in {@link InterfaceAddress} will be used.
*
* @see UUID
* @author Johann Burkard
* @version $Id: UUIDGen.java 4714 2012-03-16 11:43:28Z johann $
* @see com.eaio.uuid.UUID
*/
public final class UUIDGen {
/**
* The last time value. Used to remove duplicate UUIDs.
*/
private static AtomicLong lastTime = new AtomicLong(Long.MIN_VALUE);
/**
* The cached MAC address.
*/
private static String macAddress = null;
/**
* The current clock and node value.
*/
private static long clockSeqAndNode = 0x8000000000000000L;
static {
try {
Class.forName("java.net.InterfaceAddress");
macAddress = Class.forName(
"com.eaio.uuid.UUIDGen$HardwareAddressLookup").newInstance().toString();
}
catch (ExceptionInInitializerError err) {
// Ignored.
}
catch (ClassNotFoundException ex) {
// Ignored.
}
catch (LinkageError err) {
// Ignored.
}
catch (IllegalAccessException ex) {
// Ignored.
}
catch (InstantiationException ex) {
// Ignored.
}
catch (SecurityException ex) {
// Ignored.
}
if (macAddress == null) {
Process p = null;
BufferedReader in = null;
try {
String osname = System.getProperty("os.name", ""), osver = System.getProperty("os.version", "");
if (osname.startsWith("Windows")) {
p = Runtime.getRuntime().exec(
new String[] { "ipconfig", "/all" }, null);
}
// Solaris code must appear before the generic code
else if (osname.startsWith("Solaris")
|| osname.startsWith("SunOS")) {
if (osver.startsWith("5.11")) {
p = Runtime.getRuntime().exec(
new String[] { "dladm", "show-phys", "-m" }, null);
}
else {
String hostName = getFirstLineOfCommand("uname", "-n");
if (hostName != null) {
p = Runtime.getRuntime().exec(
new String[] { "/usr/sbin/arp", hostName },
null);
}
}
}
else if (new File("/usr/sbin/lanscan").exists()) {
p = Runtime.getRuntime().exec(
new String[] { "/usr/sbin/lanscan" }, null);
}
else if (new File("/sbin/ifconfig").exists()) {
p = Runtime.getRuntime().exec(
new String[] { "/sbin/ifconfig", "-a" }, null);
}
if (p != null) {
in = new BufferedReader(new InputStreamReader(
p.getInputStream()), 128);
String l = null;
while ((l = in.readLine()) != null) {
macAddress = MACAddressParser.parse(l);
if (macAddress != null
&& Hex.parseShort(macAddress) != 0xff) {
break;
}
}
}
}
catch (SecurityException ex) {
// Ignore it.
}
catch (IOException ex) {
// Ignore it.
}
finally {
if (p != null) {
close(in, p.getErrorStream(), p.getOutputStream());
p.destroy();
}
}
}
Random r = new Random();
if (macAddress != null) {
clockSeqAndNode |= Hex.parseLong(macAddress);
}
else {
try {
byte[] local = InetAddress.getLocalHost().getAddress();
clockSeqAndNode |= (local[0] << 24) & 0xFF000000L;
clockSeqAndNode |= (local[1] << 16) & 0xFF0000;
clockSeqAndNode |= (local[2] << 8) & 0xFF00;
clockSeqAndNode |= local[3] & 0xFF;
}
catch (UnknownHostException ex) {
clockSeqAndNode |= (long) (r.nextDouble() * 0x7FFFFFFF);
}
}
// Skip the clock sequence generation process and use random instead.
clockSeqAndNode |= (long) (r.nextDouble() * 0x3FFF) << 48;
}
/**
* Returns the current clockSeqAndNode value.
*
* @return the clockSeqAndNode value
* @see UUID#getClockSeqAndNode()
*/
public static long getClockSeqAndNode() {
return clockSeqAndNode;
}
/**
* Generates a new time field. Each time field is unique and larger than the
* previously generated time field.
*
* @return a new time value
* @see UUID#getTime()
*/
public static long newTime() {
return createTime(System.currentTimeMillis());
}
/**
* Creates a new time field from the given timestamp. Note that even identical
* values of currentTimeMillis will produce different time fields.
*
* @param currentTimeMillis the timestamp
* @return a new time value
* @see UUID#getTime()
*/
public static long createTime(long currentTimeMillis) {
long time;
// UTC time
long timeMillis = (currentTimeMillis * 10000) + 0x01B21DD213814000L;
while (true) {
long current = lastTime.get();
if (timeMillis > current) {
if (lastTime.compareAndSet(current, timeMillis)) {
break;
}
} else {
if (lastTime.compareAndSet(current, current + 1)) {
timeMillis = current + 1;
break;
}
}
}
// time low
time = timeMillis << 32;
// time mid
time |= (timeMillis & 0xFFFF00000000L) >> 16;
// time hi and version
time |= 0x1000 | ((timeMillis >> 48) & 0x0FFF); // version 1
return time;
}
/**
* Returns the MAC address. Not guaranteed to return anything.
*
* @return the MAC address, may be null
*/
public static String getMACAddress() {
return macAddress;
}
/**
* Returns the first line of the shell command.
*
* @param commands the commands to run
* @return the first line of the command
* @throws IOException
*/
static String getFirstLineOfCommand(String... commands) throws IOException {
Process p = null;
BufferedReader reader = null;
try {
p = Runtime.getRuntime().exec(commands);
reader = new BufferedReader(new InputStreamReader(
p.getInputStream()), 128);
return reader.readLine();
}
finally {
if (p != null) {
close(reader, p.getErrorStream(), p.getOutputStream());
p.destroy();
}
}
}
/**
* Scans MAC addresses for good ones.
*/
static class HardwareAddressLookup {
/**
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
String out = null;
try {
Enumeration ifs = NetworkInterface.getNetworkInterfaces();
if (ifs != null) {
while (ifs.hasMoreElements()) {
NetworkInterface iface = ifs.nextElement();
byte[] hardware = iface.getHardwareAddress();
if (hardware != null && hardware.length == 6
&& hardware[1] != (byte) 0xff) {
out = Hex.append(new StringBuilder(36), hardware).toString();
break;
}
}
}
}
catch (SocketException ex) {
// Ignore it.
}
return out;
}
}
}