import org.bouncycastle.tsp.TSPValidationException; //导入依赖的package包/类
public TimeStampToken(CMSSignedData signedData)
        throws TSPException, IOException {
    this.tsToken = signedData;

    if (!this.tsToken.getSignedContentTypeOID().equals(
            PKCSObjectIdentifiers.id_ct_TSTInfo.getId())) {
        throw new TSPValidationException(
                "ContentInfo object not for a time stamp.");
    }

    Collection signers = tsToken.getSignerInfos().getSigners();

    if (signers.size() != 1) {
        throw new IllegalArgumentException(
                "Time-stamp token signed by "
                + signers.size()
                + " signers, but it must contain just the TSA signature.");
    }

    tsaSignerInfo = (SignerInformation) signers.iterator().next();

    try {
        CMSProcessable content = tsToken.getSignedContent();
        ByteArrayOutputStream bOut = new ByteArrayOutputStream();

        content.write(bOut);

        ASN1InputStream aIn = new ASN1InputStream(
                new ByteArrayInputStream(bOut.toByteArray()));

        this.tstInfo = new TimeStampTokenInfo(TSTInfo.getInstance(aIn.readObject()));

        Attribute attr = tsaSignerInfo.getSignedAttributes().get(
                PKCSObjectIdentifiers.id_aa_signingCertificate);

        if (attr == null) {
            throw new TSPValidationException(
                    "no signing certificate attribute found, time stamp invalid.");
        }

        SigningCertificate signCert = SigningCertificate.getInstance(attr.getAttrValues().getObjectAt(0));

        this.certID = ESSCertID.getInstance(signCert.getCerts()[0]);
    } catch (CMSException e) {
        throw new TSPException(e.getMessage(), e.getUnderlyingException());
    }
}