| 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; |
| |
| /** |
| * <p> This is an implementation of {@link UniqueIdService}. |
| * |
| * @author <a href="mailto:Rafal.Krzewski@e-point.pl">Rafal Krzewski</a> |
| * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a> |
| * @version $Id$ |
| */ |
| 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 final AtomicInteger counter = new AtomicInteger(); |
| |
| |
| /** |
| * <p> Initializes the service upon first Turbine.doGet() |
| * invocation. |
| */ |
| @Override |
| public void init() |
| throws InitializationException |
| { |
| try |
| { |
| counter.set(0); |
| |
| // 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); |
| } |
| } |
| |
| /** |
| * <p> Writes a message to the log upon system shutdown. |
| */ |
| @Override |
| public void shutdown() |
| { |
| log.info("Turbine instance running at {} shutting down.", turbineURL); |
| } |
| |
| /** |
| * <p> 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; |
| } |
| |
| /** |
| * <p> 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; |
| } |
| |
| /** |
| * <p> 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(); |
| } |
| } |