myEclipse注册码如何通过代码生成

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 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);

  }catch(IOException ex){

  }

 }

}

控制台直接跑，输入userName，便可得到注册码