Java 类javax.xml.crypto.dsig.TransformService 实例源码

public static void main(String[] args) throws NoSuchAlgorithmException {
   try {
       TransformService ts = TransformService.getInstance(
           Transform.BASE64, "DOM", "SomeProviderThatDoesNotExist");
   }
   catch(NoSuchProviderException e) {
       // this is expected
   }
}

/**
 * Creates a <code>DOMTransform</code> from an element. It unmarshals any
 * algorithm-specific input parameters.
 *
 * @param transElem a Transform element
 */
public DOMTransform(Element transElem, XMLCryptoContext context,
                    Provider provider)
    throws MarshalException
{
    String algorithm = DOMUtils.getAttributeValue(transElem, "Algorithm");
    if (provider == null) {
        try {
            spi = TransformService.getInstance(algorithm, "DOM");
        } catch (NoSuchAlgorithmException e1) {
            throw new MarshalException(e1);
        }
    } else {
        try {
            spi = TransformService.getInstance(algorithm, "DOM", provider);
        } catch (NoSuchAlgorithmException nsae) {
            try {
                spi = TransformService.getInstance(algorithm, "DOM");
            } catch (NoSuchAlgorithmException e2) {
                throw new MarshalException(e2);
            }
        }
    }
    try {
        spi.init(new javax.xml.crypto.dom.DOMStructure(transElem), context);
    } catch (InvalidAlgorithmParameterException iape) {
        throw new MarshalException(iape);
    }
}

public Transform newTransform(String algorithm, XMLStructure params) throws NoSuchAlgorithmException, InvalidAlgorithmParameterException {
    TransformService spi;
    try {
        spi = TransformService.getInstance(algorithm, "DOM");
    } catch (NoSuchAlgorithmException nsae) {
        spi = TransformService.getInstance(algorithm, "DOM", getProvider());
    }
    if (params == null) {
        spi.init(null);
    } else {
        spi.init(params, null);
    }
    return new DOMTransform(spi);
}

public void dsig() throws Exception {

        Provider p = Security.getProvider("ApacheXMLDSig");
        TransformService.getInstance(Transform.XPATH, "DOM", p);
    }

/**
 * Creates a <code>DOMTransform</code>.
 *
 * @param spi the TransformService
 */
public DOMTransform(TransformService spi) {
    this.spi = spi;
}