org.openmdx.kernel.id.UUIDs Maven / Gradle / Ivy
/*
* ====================================================================
* Project: openMDX, http://www.openmdx.org/
* Description: UUIDs
* Owner: OMEX AG, Switzerland, http://www.omex.ch
* ====================================================================
*
* This software is published under the BSD license as listed below.
*
* Copyright (c) 2004-2009, OMEX AG, Switzerland
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* * Neither the name of the openMDX team nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* ------------------
*
* This product includes software developed by other organizations as
* listed in the NOTICE file.
*/
package org.openmdx.kernel.id;
import java.util.UUID;
import org.openmdx.kernel.id.cci.UUIDBuilder;
import org.openmdx.kernel.id.cci.UUIDGenerator;
import org.openmdx.kernel.id.plugin.RandomBasedUUIDGenerator;
import org.openmdx.kernel.id.plugin.TimeBasedUUIDGeneratorUsingRandomBasedNode;
import org.openmdx.kernel.loading.Classes;
import org.openmdx.kernel.log.SysLog;
/**
* UUIDs
*
* This class can be configured with system properties, e.g.
* - -Dorg.openmdx.uuid.generator=org.openmdx.kernel.id.plugin.TimeBasedUUIDGeneratorUsingRandomBasedNode (default)
*
- -Dorg.openmdx.uuid.generator=org.openmdx.kernel.id.plugin.RandomBasedUUIDGenerator
*
*/
public final class UUIDs {
/**
* Constructor
*/
private UUIDs() {
// TODO Avoid instantiation
}
/**
* The NIL UUID as specified in
* http://www.ietf.org/internet-drafts/draft-mealling-uuid-urn-03.txt.
*/
public static final UUID NIL = new UUID(0l, 0l);
/**
* The UUID generator class
*/
private static final Class generatorClass = getGeneratorClass();
/**
* Provide thread-local generators for the
newUUID method
*/
private static final ThreadLocal threadLocalGenerator = new ThreadLocal(){
/* (non-Javadoc)
* @see java.lang.ThreadLocal#initialValue()
*/
@Override
protected UUIDGenerator initialValue() {
return getGenerator();
}
};
/**
* The UUID provider system property.
*/
public static final String GENERATOR = "org.openmdx.uuid.generator";
/**
* Returns an URN representation of a UUID according to
* http://www.ietf.org/internet-drafts/draft-mealling-uuid-urn-03.txt.
*
* The UUID "f81d4fae-7dec-11d0-a765-00a0c91e6bf6" for example is
* represented as "urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6".
*
* @param uuid to be represented as URN
* p
* @return an URN corresponding to the provided uuid
*/
public static String toURN(
UUID uuid
){
return "urn:uuid:" + uuid;
}
/**
* Load the configured UUID provider
*
* If multiple threads need to generate UUIDs simultaneously then each should
* - either obtain its own
UUIDGenerator instance (for bulk usage)
* - or use
newUUID() instead (for standard usage)
*
*
* @return a UUID provider instance
*/
public static UUIDGenerator getGenerator(
){
try {
return UUIDs.generatorClass.newInstance();
} catch (Throwable throwable) {
SysLog.error(
"UUID generator acquisition failure",
throwable
);
throw new RuntimeException(
"UUID generator acquisition failure",
throwable
);
}
}
/**
* Create a UUID
*
* @return a new UUID
*/
public static UUID newUUID(){
return threadLocalGenerator.get().next();
}
/**
* Load the configured UUID provider
*
* If multiple threads need to build UUIDs simultaneously then
* each should obtain its own UUIDBuilder instance.
*
* @return a UUID provider instance
*/
public static UUIDBuilder getBuilder(
String namespace
){
return null; //...
}
/**
* Retrieve the configured UUID generator class
*
* @return the configured UUID generator class or
* RandomBasedUUIDGenerator.class in case of failure
*/
private static Class getGeneratorClass(
){
try {
return Classes.getApplicationClass(
System.getProperty(
GENERATOR,
TimeBasedUUIDGeneratorUsingRandomBasedNode.class.getName()
)
);
} catch (Throwable throwable) {
SysLog.error(
"UUID generator class acquisition failure, falling back to " + RandomBasedUUIDGenerator.class.getName(),
throwable
);
return RandomBasedUUIDGenerator.class;
}
}
}