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.util; 018 019 import java.net.InetAddress; 020 import java.net.ServerSocket; 021 022 import org.apache.commons.logging.Log; 023 import org.apache.commons.logging.LogFactory; 024 025 /** 026 * Generator for Globally unique Strings. 027 */ 028 public class UuidGenerator { 029 030 private static final transient Log LOG = LogFactory.getLog(UuidGenerator.class); 031 private static final String UNIQUE_STUB; 032 private static int instanceCount; 033 private static String hostName; 034 private String seed; 035 private long sequence; 036 037 static { 038 String stub = ""; 039 boolean canAccessSystemProps = true; 040 try { 041 SecurityManager sm = System.getSecurityManager(); 042 if (sm != null) { 043 sm.checkPropertiesAccess(); 044 } 045 } catch (SecurityException se) { 046 canAccessSystemProps = false; 047 } 048 049 if (canAccessSystemProps) { 050 try { 051 hostName = InetAddress.getLocalHost().getHostName(); 052 ServerSocket ss = new ServerSocket(0); 053 stub = "/" + ss.getLocalPort() + "-" + System.currentTimeMillis() + "/"; 054 Thread.sleep(100); 055 ss.close(); 056 } catch (Exception ioe) { 057 LOG.warn("Could not generate unique stub", ioe); 058 } 059 } else { 060 hostName = "localhost"; 061 stub = "-1-" + System.currentTimeMillis() + "-"; 062 } 063 UNIQUE_STUB = generateSanitizedId(stub); 064 } 065 066 public UuidGenerator(String prefix) { 067 synchronized (UNIQUE_STUB) { 068 this.seed = generateSanitizedId(prefix + UNIQUE_STUB + (instanceCount++) + "-"); 069 } 070 } 071 072 public UuidGenerator() { 073 this("ID-" + hostName); 074 } 075 076 /** 077 * As we have to find the hostname as a side-affect of generating a unique 078 * stub, we allow it's easy retrevial here 079 * 080 * @return the local host name 081 */ 082 public static String getHostName() { 083 return hostName; 084 } 085 086 /** 087 * Generate a unqiue id 088 */ 089 public synchronized String generateId() { 090 return this.seed + (this.sequence++); 091 } 092 093 /** 094 * Generate a unique ID - that is friendly for a URL or file system 095 * 096 * @return a unique id 097 */ 098 public String generateSanitizedId() { 099 return generateSanitizedId(generateId()); 100 } 101 102 /** 103 * Ensures that the id is friendly for a URL or file system 104 * 105 * @param id the unique id 106 * @return the id as file friendly id 107 */ 108 public static String generateSanitizedId(String id) { 109 id = id.replace(':', '-'); 110 id = id.replace('_', '-'); 111 id = id.replace('.', '-'); 112 id = id.replace('/', '-'); 113 id = id.replace('\\', '-'); 114 return id; 115 } 116 117 }