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] = 14; // 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 = n：ew Random();

      System.out.println(MakeKey(args[0], 0, r.nextInt(100000)));

  }

}

javac keygen.java

java keygen 注册用户名