MyEclipse免费使用

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

public class Test {

public static final void main(String[] args){
String subscriber = "direct"; //subscriber
String licenseNum = "500"; //Number of Licenses
String version = "100"; //版本号
String subscriptionCode = getSubscriptionCode(subscriber, version , licenseNum ,true);
System.out.println(subscriptionCode); //gLR8ZO-655055-62677056522757051
}

public static String getSubscriptionCode( String subscriber, String version, String licenseNum, boolean selected) {
Calendar cal = Calendar.getInstance();
cal.add(1, 3); //年份加三年
cal.add(6, -1); //日期减一 //当前日期20141226，到期日期则为20171225
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() : "-0812310";
String type = "YE3MB-";
String need = (new StringBuffer(String.valueOf(subscriber.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(subscriber).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);
}
}