git.gag.com Git - debian/openrocket/blob - src/net/sf/openrocket/util/UniqueID.java

   1 package net.sf.openrocket.util;
   2
   3 import java.security.MessageDigest;
   4 import java.security.NoSuchAlgorithmException;
   5 import java.util.UUID;
   6 import java.util.concurrent.atomic.AtomicInteger;
   7
   8 import net.sf.openrocket.gui.main.ExceptionHandler;
   9
  10 public class UniqueID {
  11
  12         private static AtomicInteger nextId = new AtomicInteger(1);
  13
  14         /**
  15          * Return a positive integer ID unique during this program execution.
  16          * The values are taken as sequential numbers, and will re-occur in
  17          * later executions of the program.
  18          * <p>
  19          * This method is thread-safe and fast.
  20          *
  21          * @return      a positive integer ID unique in this program execution.
  22          */
  23         public static int next() {
  24                 return nextId.getAndIncrement();
  25         }
  26
  27
  28         /**
  29          * Return a new universally unique ID string.
  30          *
  31          * @return      a unique identifier string.
  32          */
  33         public static String uuid() {
  34                 return UUID.randomUUID().toString();
  35         }
  36
  37
  38         /**
  39          * Return a hashed unique ID that contains no information whatsoever of the
  40          * originating computer.
  41          *
  42          * @return      a unique identifier string that contains no information about the computer.
  43          */
  44         public static String generateHashedID() {
  45                 String id = UUID.randomUUID().toString();
  46
  47                 try {
  48                         MessageDigest algorithm = MessageDigest.getInstance("MD5");
  49                         algorithm.reset();
  50                         algorithm.update(id.getBytes());
  51                         byte[] digest = algorithm.digest();
  52
  53                         StringBuilder sb = new StringBuilder();
  54                         for (byte b: digest) {
  55                                 sb.append(String.format("%02X", 0xFF & b));
  56                         }
  57                         id = sb.toString();
  58
  59                 } catch (NoSuchAlgorithmException e) {
  60                         ExceptionHandler.handleErrorCondition(e);
  61                         id = "" + id.hashCode();
  62                 }
  63
  64                 return id;
  65         }
  66
  67 }