/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package com.sun.xml.internal.ws.policy.sourcemodel;

import com.sun.xml.internal.ws.policy.PolicyException;

/**

 * Abstract class defines interface for policy model unmarshaller implementations that are specific to underlying

 * persistence layer.

 *

 * Code that depends on JAX-WS should use com.sun.xml.internal.ws.api.policy.ModelUnmarshaller

 * instead of this class.

 *

 * @author Marek Potociar

 * @author Fabian Ritzmann

 */

public abstract class PolicyModelUnmarshaller {

    private static final PolicyModelUnmarshaller xmlUnmarshaller = new XmlPolicyModelUnmarshaller();

    /**

     * Default constructor to ensure we have a common model unmarshaller base, but only our API classes implemented in this

     * package will be able to extend this abstract class. This is to restrict attempts of extending the class from

     * a client code.

     */

    PolicyModelUnmarshaller() {

        // nothing to intitialize

    }

    /**

     * Unmarshalls single policy source model from provided storage reference. Method expects that the storage

     * cursor to be alread placed on the start of a policy expression. Inner comments and whitespaces are skipped

     * in processing. Any other cursor position results in a PolicyException being thrown.

     *

     * @param storage reference to underlying storage that should be used for model unmarshalling

     * @return unmarshalled policy source model. If no policies are found, returns {@code null}.

     * @throws PolicyException in case of the unmarshalling problems

     */

    public abstract PolicySourceModel unmarshalModel(Object storage) throws PolicyException;

    /**

     * Factory method that returns policy model unmarshaller able to unmarshal

     * policy expressions from XML source.

     *

     * Code that depends on JAX-WS should use com.sun.xml.internal.ws.api.policy.ModelUnmarshaller.getUnmarshaller()

     * instead of this method.

     *

     * @return policy model unmarshaller able to unmarshal policy expressions from XML source.

     */

    public static PolicyModelUnmarshaller getXmlUnmarshaller() {

        return xmlUnmarshaller;

    }

}