关于根据CRL文件获得注销证书列表的问题

我现在有一个crl文件，如何用java程序获得该文件中的注销证书序列号呢？
急，有知道的吗？帮帮我！

[code="java"]

    FileInputStream fis = new FileInputStream(fCRLFile);
        CertificateFactory cf =
            CertificateFactory.getInstance(X509_CERT_TYPE);
        X509CRL crl = (X509CRL) cf.generateCRL(fis);

    int i = 0;
    Set tSet = aCrl.getRevokedCertificates();
    Iterator tIterator = tSet.iterator();
    CRLBean[] tBean = new CRLBean[tSet.size()];
    while (tIterator.hasNext()) {
        tBean[i] = new CRLBean();
        X509CRLEntry tEntry = (X509CRLEntry) tIterator.next();
        String sn = tEntry.getSerialNumber().toString(16).toUpperCase();
        String issName = aCrl.getIssuerDN().toString();
        String time = new SimpleDateFormat("yyyyMMddHHmmss")
                .format(tEntry.getRevocationDate());
        i++;
    }

[/code]