import javax.xml.crypto.dsig.TransformException; //导入依赖的package包/类
public Data canonicalize(Data data, XMLCryptoContext xc)
    throws TransformException
{
    return canonicalize(data, xc, null);
}
 

import javax.xml.crypto.dsig.TransformException; //导入依赖的package包/类
public Data transform(Data data, XMLCryptoContext context, OutputStream os) throws TransformException {
	LOG.debug("transform(data,context,os)");
	return null;
}
 

import javax.xml.crypto.dsig.TransformException; //导入依赖的package包/类
public Data canonicalize(Data data, XMLCryptoContext xc)
    throws TransformException {
    return canonicalize(data, xc, null);
}
 

import javax.xml.crypto.dsig.TransformException; //导入依赖的package包/类
/**
 * Transforms the specified data using the underlying transform algorithm.
 *
 * @param data the data to be transformed
 * @param xc the <code>XMLCryptoContext</code> containing
 *    additional context (may be <code>null</code> if not applicable)
 * @return the transformed data
 * @throws NullPointerException if <code>data</code> is <code>null</code>
 * @throws XMLSignatureException if an unexpected error occurs while
 *    executing the transform
 */
@Override
public Data transform(Data data, XMLCryptoContext xc)
    throws TransformException
{
    return spi.transform(data, xc);
}