001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.camel.impl;
018
019 import java.io.IOException;
020 import java.net.ServerSocket;
021 import java.util.concurrent.atomic.AtomicLong;
022
023 import org.apache.camel.spi.UuidGenerator;
024 import org.apache.camel.util.InetAddressUtil;
025 import org.apache.camel.util.ObjectHelper;
026 import org.slf4j.Logger;
027 import org.slf4j.LoggerFactory;
028
029 /**
030 * {@link org.apache.camel.spi.UuidGenerator} which is a fast implementation based on
031 * how <a href="http://activemq.apache.org/>Apache ActiveMQ</a> generates its UUID.
032 * <p/>
033 * This implementation is not synchronized but it leverages API which may not be accessible
034 * in the cloud (such as Google App Engine).
035 * <p/>
036 * The JVM system property {@link #PROPERTY_IDGENERATOR_PORT} can be used to set a specific port
037 * number to be used as part of the initialization process to generate unique UUID.
038 */
039 public class ActiveMQUuidGenerator implements UuidGenerator {
040
041 // use same JVM property name as ActiveMQ
042 public static final String PROPERTY_IDGENERATOR_PORT = "activemq.idgenerator.port";
043 private static final Logger LOG = LoggerFactory.getLogger(ActiveMQUuidGenerator.class);
044 private static final String UNIQUE_STUB;
045 private static int instanceCount;
046 private static String hostName;
047 private String seed;
048 private final AtomicLong sequence = new AtomicLong(1);
049 private final int length;
050
051 static {
052 String stub = "";
053 boolean canAccessSystemProps = true;
054 try {
055 SecurityManager sm = System.getSecurityManager();
056 if (sm != null) {
057 sm.checkPropertiesAccess();
058 }
059 } catch (SecurityException se) {
060 canAccessSystemProps = false;
061 }
062
063 if (canAccessSystemProps) {
064 int idGeneratorPort = 0;
065 ServerSocket ss = null;
066 try {
067 idGeneratorPort = Integer.parseInt(System.getProperty(PROPERTY_IDGENERATOR_PORT, "0"));
068 LOG.trace("Using port {}", idGeneratorPort);
069 hostName = InetAddressUtil.getLocalHostName();
070 ss = new ServerSocket(idGeneratorPort);
071 stub = "-" + ss.getLocalPort() + "-" + System.currentTimeMillis() + "-";
072 Thread.sleep(100);
073 } catch (Exception e) {
074 if (LOG.isTraceEnabled()) {
075 LOG.trace("Cannot generate unique stub by using DNS and binding to local port: " + idGeneratorPort, e);
076 } else {
077 LOG.warn("Cannot generate unique stub by using DNS and binding to local port: " + idGeneratorPort + " due " + e.getMessage());
078 }
079 // Restore interrupted state so higher level code can deal with it.
080 if (e instanceof InterruptedException) {
081 Thread.currentThread().interrupt();
082 }
083 } finally {
084 // some environments, such as a PaaS may not allow us to create the ServerSocket
085 if (ss != null) {
086 try {
087 // TODO: replace the following line with IOHelper.close(ss) when Java 6 support is dropped
088 ss.close();
089 } catch (IOException ioe) {
090 if (LOG.isTraceEnabled()) {
091 LOG.trace("Closing the server socket failed", ioe);
092 } else {
093 LOG.warn("Closing the server socket failed due " + ioe.getMessage() + ". This exception is ignored.");
094 }
095 }
096 }
097 }
098 }
099
100 // fallback to use localhost
101 if (hostName == null) {
102 hostName = "localhost";
103 }
104 hostName = sanitizeHostName(hostName);
105
106 if (ObjectHelper.isEmpty(stub)) {
107 stub = "-1-" + System.currentTimeMillis() + "-";
108 }
109 UNIQUE_STUB = stub;
110 }
111
112 public ActiveMQUuidGenerator(String prefix) {
113 synchronized (UNIQUE_STUB) {
114 this.seed = prefix + UNIQUE_STUB + (instanceCount++) + "-";
115 // let the ID be friendly for URL and file systems
116 this.seed = generateSanitizedId(this.seed);
117 this.length = seed.length() + ("" + Long.MAX_VALUE).length();
118 }
119 }
120
121 public ActiveMQUuidGenerator() {
122 this("ID-" + hostName);
123 }
124
125 /**
126 * As we have to find the hostname as a side-affect of generating a unique
127 * stub, we allow it's easy retrieval here
128 *
129 * @return the local host name
130 */
131 public static String getHostName() {
132 return hostName;
133 }
134
135 public static String sanitizeHostName(String hostName) {
136 boolean changed = false;
137
138 StringBuilder sb = new StringBuilder();
139 for (char ch : hostName.toCharArray()) {
140 // only include ASCII chars
141 if (ch < 127) {
142 sb.append(ch);
143 } else {
144 changed = true;
145 }
146 }
147
148 if (changed) {
149 String newHost = sb.toString();
150 LOG.info("Sanitized hostname from: {} to: {}", hostName, newHost);
151 return newHost;
152 } else {
153 return hostName;
154 }
155 }
156
157 public String generateUuid() {
158 StringBuilder sb = new StringBuilder(length);
159 sb.append(seed);
160 sb.append(sequence.getAndIncrement());
161 return sb.toString();
162 }
163
164 /**
165 * Generate a unique ID - that is friendly for a URL or file system
166 *
167 * @return a unique id
168 */
169 public String generateSanitizedId() {
170 return generateSanitizedId(generateUuid());
171 }
172
173 /**
174 * Ensures that the id is friendly for a URL or file system
175 *
176 * @param id the unique id
177 * @return the id as file friendly id
178 */
179 public static String generateSanitizedId(String id) {
180 id = id.replace(':', '-');
181 id = id.replace('_', '-');
182 id = id.replace('.', '-');
183 id = id.replace('/', '-');
184 return id;
185 }
186 }