Coverage Report - org.apache.commons.id.uuid.VersionFourGenerator
 
Classes in this File Line Coverage Branch Coverage Complexity
VersionFourGenerator
75%
27/36
70%
7/10
2
 
 1   
 /*
 2   
  * Licensed to the Apache Software Foundation (ASF) under one or more
 3   
  * contributor license agreements.  See the NOTICE file distributed with
 4   
  * this work for additional information regarding copyright ownership.
 5   
  * The ASF licenses this file to You under the Apache License, Version 2.0
 6   
  * (the "License"); you may not use this file except in compliance with
 7   
  * the License.  You may obtain a copy of the License at
 8   
  *
 9   
  *      http://www.apache.org/licenses/LICENSE-2.0
 10   
  *
 11   
  * Unless required by applicable law or agreed to in writing, software
 12   
  * distributed under the License is distributed on an "AS IS" BASIS,
 13   
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 14   
  * See the License for the specific language governing permissions and
 15   
  * limitations under the License.
 16   
  */
 17   
 package org.apache.commons.id.uuid;
 18   
 
 19   
 import org.apache.commons.id.IdentifierGenerator;
 20   
 
 21   
 import java.security.NoSuchAlgorithmException;
 22   
 import java.security.NoSuchProviderException;
 23   
 import java.security.SecureRandom;
 24   
 import java.util.Random;
 25   
 
 26   
 /**
 27   
  * <p>Class is responsible for generating version 4 UUID's per RFC 4122.
 28   
  * This class attempts to use a java.security.SecureRandom with
 29   
  * the following instantiation
 30   
  * <code>SecureRandom.getInstance("SHA1PRNG", "SUN")</code>. If neither secure
 31   
  * random implementation is avialable or an Exception is raised a java.util.Random
 32   
  * is used.</p>
 33   
  * <p>Note: Instantiation of SecureRandom is an expensive operation. The
 34   
  * constructor therefore creates a static member to hold the SecureRandom.
 35   
  * The first call to getInstance may take time; subsequent calls should return
 36   
  * quickly.</p>
 37   
  *
 38   
  * @author Commons-Id team
 39   
  * @version $Revision: 480488 $ $Date: 2006-11-29 08:57:26 +0000 (Wed, 29 Nov 2006) $
 40   
  *
 41   
  */
 42   
 public final class VersionFourGenerator implements IdentifierGenerator, Constants {
 43   
 
 44   
         /** Random used to generate UUID's */
 45  1 
         private static final Random regularRandom = new Random();
 46   
 
 47   
         /** SecureRandom used to generate UUID's */
 48   
         private static Random secureRandom;
 49   
 
 50   
         /** The pseudo-random number generator to use */
 51  1 
         private static String usePRNG = "SHA1PRNG";
 52   
 
 53   
         /** The pseudo-random number generator package name to use */
 54  1 
         private static String usePRNGPackage = "SUN";
 55   
 
 56   
         private static VersionFourGenerator generator;
 57   
 
 58   
         /**
 59   
          * <p>Constructs a new VersionFourGenerator.</p>
 60   
          */
 61   
         public VersionFourGenerator() {
 62  3 
             super();
 63  3 
         }
 64   
 
 65   
         /**
 66   
          * <p>Returns a singleton instance of the version four UUID generator.</p>
 67   
          *
 68   
          * @return the singleton instance of the version four UUID generator.
 69   
          */
 70   
         public static VersionFourGenerator getInstance() {
 71  1 
                 if (generator == null) {
 72  1 
                     generator = new VersionFourGenerator();
 73   
                 }
 74  1 
                 return generator;
 75   
         }
 76   
 
 77   
         /**
 78   
          * <p>Returns a new version four UUID.</p>
 79   
          *
 80   
          * @return Object a new version 4 UUID.
 81   
          */
 82   
         public Object nextIdentifier() {
 83  5 
             return nextUUID(false);
 84   
         }
 85   
 
 86   
         /**
 87   
          * <p>Returns a new version four UUID.</p>
 88   
          * <p>This overloaded method may produce both UUID's using a <code>SecureRandom</code> as well as using normal
 89   
          * <code>Random</code>
 90   
          * </p>
 91   
          *
 92   
          * @param secure indicates whether or not to use <code>SecureRandom</code> in generating the random bits.
 93   
          * @return a new version four UUID that was generated by either a <code>Random</code> or <code>SecureRandom</code>.
 94   
          */
 95   
         public Object nextIdentifier(boolean secure)  {
 96  5 
             return nextUUID(secure);
 97   
         }
 98   
 
 99   
         /**
 100   
         * <p>Returns a new version four UUID.</p>
 101   
         *
 102   
         * @return Object a new version 4 UUID.
 103   
         */
 104   
         public UUID nextUUID() {
 105   
             //Call nextUUID with secure = false
 106  1 
             return nextUUID(false);
 107   
         }
 108   
 
 109   
         /**
 110   
          * <p>Returns a new version four UUID using either <code>SecureRandom</code> or <code>Random</code>.</p>
 111   
          *
 112   
          * @param secure boolean flag indicating whether to use <code>SecureRandom</code> or <code>Random</code>.
 113   
          * @return a new version four UUID using either <code>SecureRandom</code> or <code>Random</code>.
 114   
          */
 115   
         private UUID nextUUID(boolean secure) {
 116  11 
             byte[] raw = new byte[UUID_BYTE_LENGTH];
 117  11 
             if (secure) {
 118   
                 //Initialize the secure random if null.
 119  5 
                 if (secureRandom == null) {
 120   
                     try {
 121  1 
                         if (usePRNGPackage != null) {
 122  1 
                             secureRandom = SecureRandom.getInstance(usePRNG, usePRNGPackage);
 123  1 
                         } else {
 124  0 
                             secureRandom = SecureRandom.getInstance(usePRNG);
 125   
                         }
 126  0 
                     } catch (NoSuchAlgorithmException nsae) {
 127  0 
                         secure = false; //Fail back to default PRNG/Random
 128  0 
                     } catch (NoSuchProviderException nspe) {
 129  0 
                         secure = false; //Fail back to default PRNG/Random
 130  1 
                     }
 131   
                 }
 132  5 
                 if (secureRandom != null) {
 133  5 
                     secureRandom.nextBytes(raw);
 134  5 
                 }
 135   
             } else {
 136  6 
                 regularRandom.nextBytes(raw);
 137   
             }
 138   
 
 139  11 
             raw[TIME_HI_AND_VERSION_BYTE_6] &= 0x0F;
 140  11 
             raw[TIME_HI_AND_VERSION_BYTE_6] |= (UUID.VERSION_FOUR << 4);
 141   
 
 142  11 
             raw[CLOCK_SEQ_HI_AND_RESERVED_BYTE_8] &= 0x3F; //0011 1111
 143  11 
             raw[CLOCK_SEQ_HI_AND_RESERVED_BYTE_8] |= 0x80; //1000 0000
 144   
 
 145  11 
             return new UUID(raw);
 146   
         }
 147   
 
 148   
        /**
 149   
         * <p>Allows clients to set the pseudo-random number generator implementation used when generating a version four uuid with
 150   
         * the secure option. The secure option uses a <code>SecureRandom</code>. The packageName string may be null to specify
 151   
         * no preferred package.</p>
 152   
         *
 153   
         * @param prngName the pseudo-random number generator implementation name. For example "SHA1PRNG".
 154   
         * @param packageName the package name for the PRNG provider. For example "SUN".
 155   
         */
 156   
        public static void setPRNGProvider(String prngName, String packageName) {
 157  0 
            VersionFourGenerator.usePRNG = prngName;
 158  0 
            VersionFourGenerator.usePRNGPackage = packageName;
 159  0 
            VersionFourGenerator.secureRandom = null;
 160  0 
        }
 161   
     }
Report generated by Cobertura 1.9 on 17/05/08 17:21.