java代码生成MyEclipse 注册码

import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;

public class MyEclipseRegister {

 /**
  * @param args
  */
 public static void main(String[] args)
 {
   String id="fanp";  
      String num="625";  
      System.out.println(getSerial(id,"100",num,false));  

 }
 public static String getSerial(String userId, String version,  
            String licenseNum, boolean selected) {  
        Calendar cal = Calendar.getInstance();  
        cal.add(1, 3);  
        cal.add(6, -1);  
        NumberFormat nf = new DecimalFormat("000");  
        licenseNum = nf.format(Integer.valueOf(licenseNum));  
        String verTime = selected ? (new StringBuffer("-")).append(  
                (new SimpleDateFormat("yyMMdd")).format(cal.getTime())).append(  
                "0").toString() : "-1012310";  
        String type = "YE3MB-";  
        String need = (new StringBuffer(String.valueOf(userId.substring(0, 1))))  
                .append(type).append(version).append(licenseNum)  
                .append(verTime).toString();  
        String dx = (new StringBuffer(String.valueOf(need)))  
                .append(  
                        "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.")  
                  
                        .append(userId).toString();  
        int suf = decode(dx);  
        String code = (new StringBuffer(String.valueOf(need))).append(  
                String.valueOf(suf)).toString();  
        return change(code);  
    }  
 
    private static int decode(String s) {  
        int i = 0;  
        char ac[] = s.toCharArray();  
        int j = 0;  
        for (int k = ac.length; j < k; j++)  
            i = 31 * i + ac[j];  
 
        return Math.abs(i);  
    }  
 
    private static String change(String s) {  
        byte abyte0[] = s.getBytes();  
        char ac[] = new char[s.length()];  
        int i = 0;  
        for (int k = abyte0.length; i < k; i++) {  
            int 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;  
        }  
 
        return String.valueOf(ac);  
    }  

 
 
}