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 * Copyright (c) 2003, 2005, 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

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 */

package javax.xml.validation;

/**

 * Immutable in-memory representation of grammar.

 *

 * <p>

 * This object represents a set of constraints that can be checked/

 * enforced against an XML document.

 *

 * <p>

 * A {@link Schema} object is thread safe and applications are

 * encouraged to share it across many parsers in many threads.

 *

 * <p>

 * A {@link Schema} object is immutable in the sense that it shouldn't

 * change the set of constraints once it is created. In other words,

 * if an application validates the same document twice against the same

 * {@link Schema}, it must always produce the same result.

 *

 * <p>

 * A {@link Schema} object is usually created from {@link SchemaFactory}.

 *

 * <p>

 * Two kinds of validators can be created from a {@link Schema} object.

 * One is {@link Validator}, which provides highly-level validation

 * operations that cover typical use cases. The other is

 * {@link ValidatorHandler}, which works on top of SAX for better

 * modularity.

 *

 * <p>

 * This specification does not refine

 * the {@link java.lang.Object#equals(java.lang.Object)} method.

 * In other words, if you parse the same schema twice, you may

 * still get <code>!schemaA.equals(schemaB)</code>.

 *

 * @see <a href="http://www.w3.org/TR/xmlschema-1/">XML Schema Part 1: Structures</a>

 * @see <a href="http://www.w3.org/TR/xml11/">Extensible Markup Language (XML) 1.1</a>

 * @see <a href="http://www.w3.org/TR/REC-xml">Extensible Markup Language (XML) 1.0 (Second Edition)</a>

 * @since 1.5

 */

public abstract class Schema {

    /**

     * Constructor for the derived class.

     *

     * <p>

     * The constructor does nothing.

     */

    protected Schema() {

    }

    /**

     * Creates a new {@link Validator} for this {@link Schema}.

     *

     * <p>A validator enforces/checks the set of constraints this object

     * represents.</p>

     *

     * <p>Implementors should assure that the properties set on the

     * {@link SchemaFactory} that created this {@link Schema} are also

     * set on the {@link Validator} constructed.</p>

     *

     * @return

     *      Always return a non-null valid object.

     */

    public abstract Validator newValidator();

    /**

     * Creates a new {@link ValidatorHandler} for this {@link Schema}.

     *

     * <p>Implementors should assure that the properties set on the

     * {@link SchemaFactory} that created this {@link Schema} are also

     * set on the {@link ValidatorHandler} constructed.</p>

     *

     * @return

     *      Always return a non-null valid object.

     */

    public abstract ValidatorHandler newValidatorHandler();

}