某一天打开MyEclipse，突然发现出现如下提示框：
1.错误日志
Thank you for choosing MyEclipse
Your license expired 1091 days ago.
To continue use of MyEclipse please choose "Buy" to purchase a MyEclipse license. If you already have a MyEclipse license code choose "Unlock" to enter your license details and resume use of MyEclipse
2.错误说明
感谢您选择MyEclipse
您的许可证已于1091天前过期。
要继续使用MyEclipse，请选择“购买”购买MyEclipse许可证。如果您已经拥有MyEclipse许可证代码，请选择“解锁”以输入许可证详细信息并继续使用MyEclipse
从错误日志很明显的可以看出来是由于MyEclipse注册码过期导致的，所以这时就需要我们提供新的有效的注册码即可。
1、将所在设备的系统时间回滚至注册码有效期内以确保MyEclipse正常打开使用
2、在MyEclipse中新建一个java project （命名随意，例：abc）
3、在src目录下新建一个MyEclipseGen的类将如下的代码复制到该类中，并运行。
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
public class MyEclipseGen {
public static final void main(String[] args){
String subscriber = "Fgoatyy"; //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);
}
} 4、按照提示输入注册名（随意输入），然后会自动产生注册码。
5、将设备系统时间调整正常，然后重新打开MyEclipseMyEclipse，点击Unlock按钮，按照提示输入注册名和注册码即可。
说明：
如果输入注册名和新生成的注册码后无法点击Finish按钮，说明生成的注册码无效，只需要重新运行代码直至生成有效的注册码为止（或换注册名重新生成）。
例如如下无效注册码提示：
1.过期
2.鉴别为伪造
