src/org/jcp/xml/dsig/internal/dom/DOMXPathFilter2Transform.java

/*
 * Copyright 2005 The Apache Software Foundation.
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */
/*
 * ===========================================================================
 *
 * (C) Copyright IBM Corp. 2003 All Rights Reserved.
 *
 * ===========================================================================
 */
/*
 * Portions copyright 2005 Sun Microsystems, Inc. All rights reserved.
 */
/*
 * $Id$
 */
package org.jcp.xml.dsig.internal.dom;

import javax.xml.crypto.*;
import javax.xml.crypto.dsig.*;
import javax.xml.crypto.dsig.spec.TransformParameterSpec;
import javax.xml.crypto.dsig.spec.XPathType;
import javax.xml.crypto.dsig.spec.XPathFilter2ParameterSpec;
import java.security.InvalidAlgorithmParameterException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.HashMap;
import org.w3c.dom.Attr;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;

/**
 * DOM-based implementation of XPath Filter 2.0 Transform.
 * (Uses Apache XML-Sec Transform implementation)
 *
 * @author Joyce Leung
 */
public final class DOMXPathFilter2Transform extends ApacheTransform {

    public void init(TransformParameterSpec params)
        throws InvalidAlgorithmParameterException {
        if (params == null) {
	    throw new InvalidAlgorithmParameterException("params are required");
	} else if (!(params instanceof XPathFilter2ParameterSpec)) {
	    throw new InvalidAlgorithmParameterException
		("params must be of type XPathFilter2ParameterSpec");
        }
	this.params = params;
    }

    public void init(XMLStructure parent, XMLCryptoContext context)
        throws InvalidAlgorithmParameterException {

	super.init(parent, context);
	try {
	    unmarshalParams(DOMUtils.getFirstChildElement(transformElem));
	} catch (MarshalException me) {
	    throw (InvalidAlgorithmParameterException)
		new InvalidAlgorithmParameterException().initCause(me);
	}
    }

    private void unmarshalParams(Element curXPathElem) throws MarshalException {
        List list = new ArrayList();
	while (curXPathElem != null) {
	    String xPath = curXPathElem.getFirstChild().getNodeValue();
	    String filterVal = 
		DOMUtils.getAttributeValue(curXPathElem, "Filter");
	    if (filterVal == null) {
		throw new MarshalException("filter cannot be null");
	    }
	    XPathType.Filter filter = null;
            if (filterVal.equals("intersect")) {
                filter = XPathType.Filter.INTERSECT;
            } else if (filterVal.equals("subtract")) {   
                filter = XPathType.Filter.SUBTRACT;
            } else if (filterVal.equals("union")) {
                filter = XPathType.Filter.UNION;
            } else {
                throw new MarshalException("Unknown XPathType filter type" 
		    + filterVal);
            }
	    NamedNodeMap attributes = curXPathElem.getAttributes();
	    if (attributes != null) {
		int length = attributes.getLength();
	        Map namespaceMap = new HashMap(length);
	        for (int i = 0; i < length; i++) {
	    	    Attr attr = (Attr) attributes.item(i);
	    	    String prefix = attr.getPrefix();
	    	    if (prefix != null && prefix.equals("xmlns")) {
	                namespaceMap.put(attr.getLocalName(), attr.getValue());
            	    }
                }
	        list.add(new XPathType(xPath, filter, namespaceMap));
	    } else {
	        list.add(new XPathType(xPath, filter));
	    }

	    curXPathElem = DOMUtils.getNextSiblingElement(curXPathElem);
	}
        this.params = new XPathFilter2ParameterSpec(list);
    }

    public void marshalParams(XMLStructure parent, XMLCryptoContext context)
        throws MarshalException {

	super.marshalParams(parent, context);
	XPathFilter2ParameterSpec xp = 
	    (XPathFilter2ParameterSpec) getParameterSpec();
        String prefix = DOMUtils.getNSPrefix(context, Transform.XPATH2);
	String qname = (prefix == null) ? "xmlns" : "xmlns:" + prefix;
	List list = xp.getXPathList();
	for (int i = 0, size = list.size(); i < size; i++) {
            XPathType xpathType = (XPathType) list.get(i);
            Element elem = DOMUtils.createElement
                (ownerDoc, "XPath", Transform.XPATH2, prefix);
            elem.appendChild
		(ownerDoc.createTextNode(xpathType.getExpression()));
	    DOMUtils.setAttribute
		(elem, "Filter", xpathType.getFilter().toString());
            elem.setAttributeNS("http://www.w3.org/2000/xmlns/", qname, 
	        Transform.XPATH2);

            // add namespace attributes, if necessary
            Iterator it = xpathType.getNamespaceMap().entrySet().iterator();
            while (it.hasNext()) {
                Map.Entry entry = (Map.Entry) it.next();
                elem.setAttributeNS("http://www.w3.org/2000/xmlns/", "xmlns:"
                    + (String) entry.getKey(), (String) entry.getValue());
            }

            transformElem.appendChild(elem);
        }
    }
}