org.apache.turbine.services.uniqueid.TurbineUniqueIdService Maven / Gradle / Ivy
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package org.apache.turbine.services.uniqueid;
import java.nio.charset.StandardCharsets;
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
import java.security.MessageDigest;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.commons.codec.binary.Base64;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.turbine.Turbine;
import org.apache.turbine.services.InitializationException;
import org.apache.turbine.services.TurbineBaseService;
import org.apache.turbine.util.GenerateUniqueId;
/**
* This is an implementation of {@link UniqueIdService}.
*
* @author Rafal Krzewski
* @author Henning P. Schmiedehausen
* @version $Id: TurbineUniqueIdService.java 1854787 2019-03-04 18:30:25Z tv $
*/
public class TurbineUniqueIdService
extends TurbineBaseService
implements UniqueIdService
{
/** Logging */
private static final Logger log = LogManager.getLogger(TurbineUniqueIdService.class);
/** The identifier of this instance of turbine. */
private static String turbineId = "UNKNOWN";
private static String turbineURL = "UNKNOWN";
private static AtomicInteger counter;
/**
*
Initializes the service upon first Turbine.doGet()
* invocation.
*/
@Override
public void init()
throws InitializationException
{
try
{
counter = new AtomicInteger();
// This might be a problem if the unique Id Service runs
// before Turbine got its first request. In this case,
// getDefaultServerData will return just a dummy value
// which is the same for all instances of Turbine.
//
// TODO This needs definitely further working.
turbineURL = Turbine.getDefaultServerData().toString();
MessageDigest md = MessageDigest.getInstance("MD5");
byte [] bytesId = md.digest(turbineURL.getBytes(StandardCharsets.UTF_8));
turbineId = new String(Base64.encodeBase64(bytesId),
StandardCharsets.UTF_8);
log.info("This is Turbine instance running at: {}", turbineURL);
log.info("The instance id is #{}", turbineId);
setInit(true);
}
catch (Exception e)
{
throw new InitializationException(
"Could not initialize TurbineUniqueId Service", e);
}
}
/**
*
Writes a message to the log upon system shutdown.
*/
@Override
public void shutdown()
{
log.info("Turbine instance running at {} shutting down.", turbineURL);
}
/**
*
Returns an identifier of this Turbine instance that is unique
* both on the server and worldwide. This identifier is computed
* as an MD5 sum of the URL (including schema, address, port if
* different that 80/443 respectively, context and servlet name).
* There is an overwhelming probability that this id will be
* different that all other Turbine instances online.
*
* @return A String with the instance identifier.
*/
@Override
public String getInstanceId()
{
return turbineId;
}
/**
*
Returns an identifier that is unique within this turbine
* instance, but does not have random-like appearance.
*
* @return A String with the non-random looking instance
* identifier.
*/
@Override
public String getUniqueId()
{
int current = counter.getAndIncrement();
String id = Integer.toString(current);
// If you manage to get more than 100 million of ids, you'll
// start getting ids longer than 8 characters.
if (current < 100000000)
{
id = ("00000000" + id).substring(id.length());
}
return id;
}
/**
*
Returns a unique identifier that looks like random data.
*
* @return A String with the random looking instance identifier.
*/
@Override
public String getPseudorandomId()
{
return GenerateUniqueId.getIdentifier();
}
}