轉載來源不明，僅供大家了解其中的java相關的知識

JIRA可真是個好東西啊,自定義能力超強,雖然主要是用來做bug跟蹤治理的,但是很輕易的就可以改造成項目治理系統.只可惜是要收費的,為了使用它,sorry啊,只好下載了一個注冊機.不過下載的注冊機是JIRA3.0版的,現在的JIRA已經出到3.1版了.試了一下發現注冊機不行用.幾乎放棄了就,但是仔細分析了一下JIRA的包的結構,發現注冊機不行用很可能是因為3.1版的包結構改變了,破解需要的那個licence包的位置變掉了.于是抱著僥幸心理把下載的注冊機keygen.class反編譯了一下,結果發現注冊機沒有被混淆過,很輕易就看到了所有的代碼,于是就將注冊機import的包名改了一下,重新編譯,呃,可以用了,真是對不起,做了錯事了.

 // Decompiled by DJ v3.7.7.81 Copyright 2004 Atanas Neshkov  Date: 2005-2-26 22:13:16
// Home Page : http://members.fortunecity.com/neshkov/dj.Html  - Check often for new version!
// Decompiler options: packimports(3)
// Source File Name:   keygen.java

import com.atlassian.License.LicensePair;
import java.io.*;
import java.security.KeyFactory;
import java.security.Signature;
import java.security.spec.PKCS8EncodedKeySpec;

public class keygen
{

    public keygen()
    {
    }

    public static void main(String args[])
        throws IOException
    {
        try
        {
            long l = 267L;
            long l1 = System.currentTimeMillis();
            long l2 = System.currentTimeMillis();
            String s = "";
            System.out.PRintln("Keygen for JIRA Enterprise Edition.");
            System.out.print("created by mydaj[ROR].");
            do
            {
                System.out.print("/nEnter your organization name: ");
                for(int i = System.in.read(); i != 10 && i != 13; i = System.in.read())
                    s = s + (char)i;

            } while(s == "");
            try
            {
                PKCS8EncodedKeySpec pkcs8encodedkeyspec = new PKCS8EncodedKeySpec(EncodedPrvKey);
                KeyFactory keyfactory = KeyFactory.getInstance("DSA", "SUN");
                java.security.PrivateKey privatekey = keyfactory.generatePrivate(pkcs8encodedkeyspec);
                String s1 = Long.toString(l, 10);
                s1 = s1 + "^^";
                s1 = s1 + Long.toString(l1, 10);
                s1 = s1 + "^^";
                s1 = s1 + Long.toString(l2, 10);
                s1 = s1 + "^^";
                s1 = s1 + s;
                byte abyte0[] = s1.getBytes();
                Signature signature = Signature.getInstance("SHA1withDSA");
                signature.initSign(privatekey);
                signature.update(abyte0);
                byte abyte1[] = signature.sign();
                LicensePair licensepair = null;
                try
                {
                    licensepair = new LicensePair(abyte0, abyte1);
                }
                catch(Exception exception1)
                {
                    exception1.printStackTrace();
                }
                System.out.println(s1);
                System.out.println("Your license key is: ");
                System.out.println(licensepair.toString());
            }
            catch(Exception exception)
            {
                exception.printStackTrace();
            }
        }
        catch(IOException ioexception) { }
    }