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10   *
11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
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17   * You should have received a copy of the GNU General Public License version
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19   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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25  
26  package javax.xml.validation;
27  
28  /**
29   * Immutable in-memory representation of grammar.
30   *
31   * <p>
32   * This object represents a set of constraints that can be checked/
33   * enforced against an XML document.
34   *
35   * <p>
36   * A {@link Schema} object is thread safe and applications are
37   * encouraged to share it across many parsers in many threads.
38   *
39   * <p>
40   * A {@link Schema} object is immutable in the sense that it shouldn't
41   * change the set of constraints once it is created. In other words,
42   * if an application validates the same document twice against the same
43   * {@link Schema}, it must always produce the same result.
44   *
45   * <p>
46   * A {@link Schema} object is usually created from {@link SchemaFactory}.
47   *
48   * <p>
49   * Two kinds of validators can be created from a {@link Schema} object.
50   * One is {@link Validator}, which provides highly-level validation
51   * operations that cover typical use cases. The other is
52   * {@link ValidatorHandler}, which works on top of SAX for better
53   * modularity.
54   *
55   * <p>
56   * This specification does not refine
57   * the {@link java.lang.Object#equals(java.lang.Object)} method.
58   * In other words, if you parse the same schema twice, you may
59   * still get <code>!schemaA.equals(schemaB)</code>.
60   *
61   * @author <a href="mailto:Kohsuke.Kawaguchi@Sun.com">Kohsuke Kawaguchi</a>
62   * @see <a href="http://www.w3.org/TR/xmlschema-1/">XML Schema Part 1: Structures</a>
63   * @see <a href="http://www.w3.org/TR/xml11/">Extensible Markup Language (XML) 1.1</a>
64   * @see <a href="http://www.w3.org/TR/REC-xml">Extensible Markup Language (XML) 1.0 (Second Edition)</a>
65   * @since 1.5
66   */
67  public abstract class Schema {
68  
69      /**
70       * Constructor for the derived class.
71       *
72       * <p>
73       * The constructor does nothing.
74       */
75      protected Schema() {
76      }
77  
78      /**
79       * Creates a new {@link Validator} for this {@link Schema}.
80       *
81       * <p>A validator enforces/checks the set of constraints this object
82       * represents.</p>
83       *
84       * <p>Implementors should assure that the properties set on the
85       * {@link SchemaFactory} that created this {@link Schema} are also
86       * set on the {@link Validator} constructed.</p>
87       *
88       * @return
89       *      Always return a non-null valid object.
90       */
91      public abstract Validator newValidator();
92  
93      /**
94       * Creates a new {@link ValidatorHandler} for this {@link Schema}.
95       *
96       * <p>Implementors should assure that the properties set on the
97       * {@link SchemaFactory} that created this {@link Schema} are also
98       * set on the {@link ValidatorHandler} constructed.</p>
99       *
100      * @return
101      *      Always return a non-null valid object.
102      */
103     public abstract ValidatorHandler newValidatorHandler();
104 }