import java.math.BigInteger;import java.util.Date;import java.util.Random;import java.util.zip.CRC32;public class Keygen{  /**  * @param s  * @param i  * @param bytes  * @return  */  public static short getCRC(String s, int i, byte bytes[])  {      CRC32 crc32 = new CRC32();      if (s != null)      {          for (int j = 0; j < s.length(); j++)          {              char c = s.charAt(j);              crc32.update(c);          }      }      crc32.update(i);      crc32.update(i >> 8);      crc32.update(i >> 16);      crc32.update(i >> 24);      for (int k = 0; k < bytes.length - 2; k++)      {          byte byte0 = bytes[k];          crc32.update(byte0);      }      return (short) (int) crc32.getValue();  }  /**  * @param biginteger  * @return String  */  public static String encodeGroups(BigInteger biginteger)  {      BigInteger beginner1 = BigInteger.valueOf(0x39aa400L);      StringBuilder sb = new StringBuilder();      for (int i = 0; biginteger.compareTo(BigInteger.ZERO) != 0; i++)      {          int j = biginteger.mod(beginner1).intValue();          String s1 = encodeGroup(j);          if (i > 0)          {              sb.append("-");          }          sb.append(s1);          biginteger = biginteger.divide(beginner1);      }      return sb.toString();  }  /**  * @param i  * @return  */  public static String encodeGroup(int i)  {      StringBuilder sb = new StringBuilder();      for (int j = 0; j < 5; j++)      {          int k = i % 36;          char c;          if (k < 10)          {              c = (char) (48 + k);          }          else          {              c = (char) ((65 + k) - 10);          }          sb.append(c);          i /= 36;      }      return sb.toString();  }  /**  * @param name  * @param days  * @param id  * @param prtype  * @return  */  public static String MakeKey(String name, int days, int id)  {      id %= 100000;      byte bkey[] = new byte[12];      bkey[0] = (byte) 1; // Product type: IntelliJ IDEA is 1      bkey[1] = 13; // version      Date d = new Date();      long ld = (d.getTime() >> 16);      bkey[2] = (byte) (ld & 255);      bkey[3] = (byte) ((ld >> 8) & 255);      bkey[4] = (byte) ((ld >> 16) & 255);      bkey[5] = (byte) ((ld >> 24) & 255);      days &= 0xffff;      bkey[6] = (byte) (days & 255);      bkey[7] = (byte) ((days >> 8) & 255);      bkey[8] = 105;      bkey[9] = -59;      bkey[10] = 0;      bkey[11] = 0;      int w = getCRC(name, id % 100000, bkey);      bkey[10] = (byte) (w & 255);      bkey[11] = (byte) ((w >> 8) & 255);      BigInteger pow = new BigInteger("89126272330128007543578052027888001981", 10);      BigInteger mod = new BigInteger("86f71688cdd2612ca117d1f54bdae029", 16);      BigInteger k0 = new BigInteger(bkey);      BigInteger k1 = k0.modPow(pow, mod);      String s0 = Integer.toString(id);      String sz = "0";      while (s0.length() != 5)      {          s0 = sz.concat(s0);      }      s0 = s0.concat("-");      String s1 = encodeGroups(k1);      s0 = s0.concat(s1);      return s0;  }  public static void main(String[] args)  {      if (args.length == 0)      {          System.err.printf("*** Usage: %s name%n", Keygen.class.getCanonicalName());          System.exit(1);      }      Random r = new Random();      System.out.println(MakeKey(args[0], 0, r.nextInt(100000)));  }}

public static void main(String[] args)  {      Random r = new Random();      System.out.println(MakeKey(“xxx”, 0, r.nextInt(100000)));  }