ExcC14NParameterSpec.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
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/*
 * $Id: ExcC14NParameterSpec.java,v 1.7 2005/05/13 18:45:42 mullan Exp $
 */
package javax.xml.crypto.dsig.spec;

import javax.xml.crypto.dsig.CanonicalizationMethod;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * Parameters for the W3C Recommendation:
 * <a href="http://www.w3.org/TR/xml-exc-c14n/">
 * Exclusive XML Canonicalization (C14N) algorithm</a>. The
 * parameters include an optional inclusive namespace prefix list. The XML
 * Schema Definition of the Exclusive XML Canonicalization parameters is
 * defined as:
 * <pre><code>
 * <schema xmlns="http://www.w3.org/2001/XMLSchema"
 *         xmlns:ec="http://www.w3.org/2001/10/xml-exc-c14n#"
 *         targetNamespace="http://www.w3.org/2001/10/xml-exc-c14n#"
 *         version="0.1" elementFormDefault="qualified">
 *
 * <element name="InclusiveNamespaces" type="ec:InclusiveNamespaces"/>
 * <complexType name="InclusiveNamespaces">
 *   <attribute name="PrefixList" type="xsd:string"/>
 * </complexType>
 * </schema>
 * </code></pre>
 *
 * @author Sean Mullan
 * @author JSR 105 Expert Group
 * @since 1.6
 * @see CanonicalizationMethod
 */
public final class ExcC14NParameterSpec implements C14NMethodParameterSpec {

    private final List<String> prefixList;

    /**
     * Indicates the default namespace ("#default").
     */
    public static final String DEFAULT = "#default";

    /**
     * Creates a <code>ExcC14NParameterSpec</code> with an empty prefix
     * list.
     */
    public ExcC14NParameterSpec() {
        prefixList = Collections.emptyList();
    }

    /**
     * Creates a <code>ExcC14NParameterSpec</code> with the specified list
     * of prefixes. The list is copied to protect against subsequent
     * modification.
     *
     * @param prefixList the inclusive namespace prefix list. Each entry in
     *    the list is a <code>String</code> that represents a namespace prefix.
     * @throws NullPointerException if <code>prefixList</code> is
     *    <code>null</code>
     * @throws ClassCastException if any of the entries in the list are not
     *    of type <code>String</code>
     */
    public ExcC14NParameterSpec(List<String> prefixList) {
        if (prefixList == null) {
            throw new NullPointerException("prefixList cannot be null");
        }
        List<String> tempList = Collections.checkedList(new ArrayList<>(),
                                                        String.class);
        tempList.addAll(prefixList);
        this.prefixList = Collections.unmodifiableList(tempList);
    }

    /**
     * Returns the inclusive namespace prefix list. Each entry in the list
     * is a <code>String</code> that represents a namespace prefix.
     *
     * <p>This implementation returns an {@link
     * java.util.Collections#unmodifiableList unmodifiable list}.
     *
     * @return the inclusive namespace prefix list (may be empty but never
     *    <code>null</code>)
     */
    public List<String> getPrefixList() {
        return prefixList;
    }
}