1 import java.io.BufferedReader;
 2 import java.io.IOException;
 3 import java.io.InputStreamReader;
 4 public class MyEclipseGen {
 5     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.";
 6     public String getSerial(String userId, String licenseNum) {
 7         java.util.Calendar cal = java.util.Calendar.getInstance();
 8         cal.add(1, 3);
 9         cal.add(6, -1);
10         java.text.NumberFormat nf = new java.text.DecimalFormat("000");
11         licenseNum = nf.format(Integer.valueOf(licenseNum));
12         String verTime = new StringBuilder("-").append(new java.text.
13                 SimpleDateFormat("yyMMdd").format(cal.getTime())).append("0").
14                          toString();
15         String type = "YE3MP-";
16         String need = new StringBuilder(userId.substring(0, 1)).append(type).
17                       append("300").append(licenseNum).append(verTime).toString();
18         String dx = new StringBuilder(need).append(LL).append(userId).toString();
19         int suf = this.decode(dx);
20         String code = new StringBuilder(need).append(String.valueOf(suf)).
21                       toString();
22         return this.change(code);
23     }
24     private int decode(String s) {
25         int i;
26         char[] ac;
27         int j;
28         int k;
29         i = 0;
30         ac = s.toCharArray();
31         j = 0;
32         k = ac.length;
33         while (j < k) {
34             i = (31 * i) + ac[j];
35             j++;
36         }
37         return Math.abs(i);
38     }
39     private String change(String s) {
40         byte[] abyte0;
41         char[] ac;
42         int i;
43         int k;
44         int j;
45         abyte0 = s.getBytes();
46         ac = new char[s.length()];
47         i = 0;
48         k = abyte0.length;
49         while (i < k) {
50             j = abyte0[i];
51             if ((j >= 48) && (j <= 57)) {
52                 j = (((j - 48) + 5) % 10) + 48;
53             } else if ((j >= 65) && (j <= 90)) {
54                 j = (((j - 65) + 13) % 26) + 65;
55             } else if ((j >= 97) && (j <= 122)) {
56                 j = (((j - 97) + 13) % 26) + 97;
57             }
58             ac[i] = (char) j;
59             i++;
60         }
61         return String.valueOf(ac);
62     }
63     public MyEclipseGen() {
64         super();
65     }
66     public static void main(String[] args) {
67         try {
68             System.out.println("please input register name:");
69             BufferedReader reader = new BufferedReader(new InputStreamReader(
70                     System.in));
71             String userId = null;
72             userId = reader.readLine();
73             MyEclipseGen myeclipsegen = new MyEclipseGen();
74             String res = myeclipsegen.getSerial(userId, "20");
75             System.out.println("Serial:" + res);
76             reader.readLine();
77         } catch (IOException ex) {
78         }
79     }
80 }