Step：
1、建立一个任意名称的Java Project
2、在该工程中建立一个名文MyEclipseGen的Java文件(MyEclipseGen.java)
3、运行下面的代码，会在控制台出现" please input register name:"，输入任意一个名字，回车后生成序列号
4、点击 MyEclipse菜单中Window→Preferences→MyEclipse→Subscription，在右侧点击“Enter Subscription”
5、在弹出框中Subscriber中输入第3步的名字，在Subscription Code中输入第3步生成的序列号
Code：
import
java.io.BufferedReader;import
java.io.IOException;import
java.io.InputStreamReader;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,
"5"); System.out.println("Serial:"
+ res); reader.readLine(); }
catch (IOException ex) { }}}原文：http://www.cnblogs.com/chendongbky/p/4537843.html