org.duuba.xades.XadesElement Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of xades Show documentation
An open source library for creating Xades signatures as specified in the ETSI specifications TS 101 903 v1.4.1 and EN 319 132 v1.1.1
The newest version!
/*******************************************************************************
 * Copyright (C) 2021 The Duuba team
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see .
 ******************************************************************************/
package org.duuba.xades;

import javax.xml.crypto.MarshalException;
import javax.xml.crypto.XMLCryptoContext;
import javax.xml.namespace.QName;

import org.apache.jcp.xml.dsig.internal.dom.DOMStructure;
import org.apache.jcp.xml.dsig.internal.dom.XmlWriter;

/**
 * Is a base class for the Xades specific elements in a signature to ensure consistent namespace prefixes when the DOM
 * tree is created.
 * 
 * @author Sander Fieten (sander at chasquis-messaging.com)
 */
public abstract class XadesElement extends DOMStructure {

	/**
	 * Gets the qualified name of the element. 
	 * NOTE: When the returned qualified name includes a namespace prefix it is only used if the context does not
	 * already specify a prefix for the URI of the element's namespace.  
	 * 
	 * @return	QName of the element
	 */
	protected abstract QName getName();
	
	/**
	 * Writes the element's content, i.e. attributes and child elements to the document tree. The element start and end
	 * are done by this base class. 
	 * 
	 * @param xwriter		XML Writer to create the document tree 
	 * @param nsPrefix		namespace prefix of this element
	 * @param dsPrefix		prefix for the XML Signature namespace
	 * @param context		the current context
	 * @throws MarshalException when the object tree for the content of this element cannot be created
	 */
	protected abstract void writeContent(XmlWriter xwriter, String nsPrefix, String dsPrefix, XMLCryptoContext context)
											throws MarshalException;	
	
	@Override
	public void marshal(XmlWriter xwriter, String dsPrefix, XMLCryptoContext context) throws MarshalException {
		final QName elementName = getName();
		final String nsURI = elementName.getNamespaceURI();
		final String nsPrefix = context.getNamespacePrefix(nsURI, elementName.getPrefix());
		
		xwriter.writeStartElement(nsPrefix, elementName.getLocalPart(), nsURI);		
		writeContent(xwriter, nsPrefix, dsPrefix, context);		
		xwriter.writeEndElement();
	}
	
	/**
	 * Base implementation of {@link Object#equals(Object)} that checks if the other object is an instance of the same 
	 * class (and hence of XadesElement) and has the same QName as the current instance. 
	 * 
	 * @param o		the other object to compare with
	 * @return		true iff o is of the same type and has the same qualified name
	 */
	@Override
	public boolean equals(Object o) {
		if (o == null)
			return false;
		if (!this.getClass().equals(o.getClass()))
			return false;
		else if (!getName().equals(((XadesElement) o).getName()))
			return false;
		else
			return true;
	}
}