My Eclipse Enterprise Workbench pj 程序

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class MyEclipseGen {
  private static final String LL = "Decompiling this copyrighted software is a violation of both your license agreement and the Digital Millenium Copyright Act of 1998 (http://www.loc.gov/copyright/legislation/dmca.pdf). Under section 1204 of the DMCA, penalties range up to a $500,000 fine or up to five years imprisonment for a first offense. Think about it; pay for a license, avoid prosecution, and feel better about yourself.";

  public String getSerial(String userId, String licenseNum) {
    java.util.Calendar cal = java.util.Calendar.getInstance();
    cal.add(1, 3);
    cal.add(6, -1);
    java.text.NumberFormat nf = new java.text.DecimalFormat("000");
    licenseNum = nf.format(Integer.valueOf(licenseNum));
    String verTime = new StringBuilder("-").append(
        new java.text.SimpleDateFormat("yyMMdd").format(cal.getTime()))
        .append("0").toString();
    String type = "YE3MP-";
    String need = new StringBuilder(userId.substring(0, 1)).append(type)
        .append("300").append(licenseNum).append(verTime).toString();
    String dx = new StringBuilder(need).append(LL).append(userId)
        .toString();
    int suf = this.decode(dx);
    String code = new StringBuilder(need).append(String.valueOf(suf))
        .toString();
    return this.change(code);
  }

  private int decode(String s) {
    int i;
    char[] ac;
    int j;
    int k;
    i = 0;
    ac = s.toCharArray();
    j = 0;
    k = ac.length;
    while (j < k) {
      i = (31 * i) + ac[j];
      j++;
    }
    return Math.abs(i);
  }

  private String change(String s) {
    byte[] abyte0;
    char[] ac;
    int i;
    int k;
    int j;
    abyte0 = s.getBytes();
    ac = new char[s.length()];
    i = 0;
    k = abyte0.length;
    while (i < k) {
      j = abyte0[i];
      if ((j >= 48) && (j <= 57)) {
        j = (((j - 48) + 5) % 10) + 48;
      } else if ((j >= 65) && (j <= 90)) {
        j = (((j - 65) + 13) % 26) + 65;
      } else if ((j >= 97) && (j <= 122)) {
        j = (((j - 97) + 13) % 26) + 97;
      }
      ac[i] = (char) j;
      i++;
    }
    return String.valueOf(ac);
  }

  public MyEclipseGen() {
    super();
  }

  public static void main(String[] args) {
    try {
      System.out.println("please input register name:");
      BufferedReader reader = new BufferedReader(new InputStreamReader(
          System.in));
      String userId = null;
      userId = reader.readLine();
      MyEclipseGen myeclipsegen = new MyEclipseGen();
      String res = myeclipsegen.getSerial(userId, "5");
      System.out.println("Serial:" + res);
      reader.readLine();
    } catch (IOException ex) {
    }
  }
}