MyEclipse 注册码生成代码

无他，在网上看了一个 MyEclipse 注册码生成代码，运行该类后，只需在控制台输入用户名，便能生成相应的注册码，很强。（没仔细研究过它的代码，原理）现献上源码：

import java.io.*;

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, "20"); //无限制版将20改成0

System.out.println("Serial:" + res);

reader.readLine();

} catch (IOException ex) {

}

}

}