1 import java.text.DecimalFormat;
 2 import java.text.NumberFormat;
 3 import java.text.SimpleDateFormat;
 4 import java.util.Calendar;
 5
 6 public class MyEclipseKeyGen {
 7
 8     public static final void main(String[] args){
 9         String subscriber = "yuxinwangjing";  //subscriber
10         String licenseNum = "500";  //Number of Licenses
11         String version = "100"; //版本号
12         String subscriptionCode = getSubscriptionCode(subscriber, version , licenseNum ,true);
13         System.out.println(subscriptionCode);
14     }
15
16     public static String getSubscriptionCode(String subscriber, String version, String licenseNum, boolean selected) {
17         Calendar cal = Calendar.getInstance();
18         cal.add(1, 3);  //年份加三年
19         cal.add(6, -1);  //日期减一,当前日期20141226，到期日期则为20171225
20         NumberFormat nf = new DecimalFormat("000");
21         licenseNum = nf.format(Integer.valueOf(licenseNum));
22         String verTime = selected ? (new StringBuffer("-")).append((new SimpleDateFormat("yyMMdd")).format(cal.getTime())).append("0").toString() : "-0812310";
23         String type = "YE3MB-";
24         String need = (new StringBuffer(String.valueOf(subscriber.substring(0,1)))).append(type).append(version).append(licenseNum).append(verTime).toString();
25         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();
26         int suf = decode(dx);
27         String code = (new StringBuffer(String.valueOf(need))).append(String.valueOf(suf)).toString();
28         return change(code);
29     }
30
31     private static int decode(String s) {
32
33         int i = 0;
34         char ac[] = s.toCharArray();
35         int j = 0;
36         for (int k = ac.length; j < k; j++)
37         i = 31 * i + ac[j];
38         return Math.abs(i);
39     }
40
41     private static String change(String s) {
42         byte abyte0[] = s.getBytes();
43         char ac[] = new char[s.length()];
44         int i = 0;
45         for (int k = abyte0.length; i < k; i++) {
46             int j = abyte0[i];
47             if (j >= 48 && j <= 57)
48             j = ((j - 48) + 5) % 10 + 48;
49             else if (j >= 65 && j <= 90)
50             j = ((j - 65) + 13) % 26 + 65;
51             else if (j >= 97 && j <= 122)
52             j = ((j - 97) + 13) % 26 + 97;
53             ac[i] = (char) j;
54         }
55         return String.valueOf(ac);
56     }
57 }