/*

 * Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

 * 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 javax.xml.transform;

/**

 * An object that implements this interface contains the information

 * needed to act as source input (XML source or transformation instructions).

 *

 * @since 1.4

 */

public interface Source {

    /**

     * Set the system identifier for this Source.

     *

     * <p>The system identifier is optional if the source does not

     * get its data from a URL, but it may still be useful to provide one.

     * The application can use a system identifier, for example, to resolve

     * relative URIs and to include in error messages and warnings.</p>

     *

     * @param systemId The system identifier as a URL string.

     */

    public void setSystemId(String systemId);

    /**

     * Get the system identifier that was set with setSystemId.

     *

     * @return The system identifier that was set with setSystemId, or null

     * if setSystemId was not called.

     */

    public String getSystemId();

    /**

     * Indicates whether the {@code Source} object is empty. Empty means

     * that there is no input available from this Source.

     *

     * @implSpec The default implementation of this method throws

     * {@link UnsupportedOperationException}.

     *

     * @return true if the {@code Source} object is empty, false otherwise

     */

    default boolean isEmpty() {

        throw new UnsupportedOperationException("The isEmpty method is not supported.");

    }

}