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1   /*
2    * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4    *
5    * This code is free software; you can redistribute it and/or modify it
6    * under the terms of the GNU General Public License version 2 only, as
7    * published by the Free Software Foundation.  Oracle designates this
8    * particular file as subject to the "Classpath" exception as provided
9    * by Oracle in the LICENSE file that accompanied this code.
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).
16   *
17   * You should have received a copy of the GNU General Public License version
18   * 2 along with this work; if not, write to the Free Software Foundation,
19   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20   *
21   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22   * or visit www.oracle.com if you need additional information or have any
23   * questions.
24   */
25  
26  package com.sun.tools.internal.xjc;
27  
28  import java.net.URL;
29  
30  import javax.xml.validation.Schema;
31  import javax.xml.validation.SchemaFactory;
32  import javax.xml.validation.ValidatorHandler;
33  
34  import com.sun.xml.internal.bind.v2.util.XmlFactory;
35  import javax.xml.XMLConstants;
36  import org.xml.sax.SAXException;
37  
38  import static com.sun.xml.internal.bind.v2.util.XmlFactory.allowExternalAccess;
39  
40  /**
41   * Wraps a JAXP {@link Schema} object and lazily instantiate it.
42   *
43   * This object is thread-safe. There should be only one instance of
44   * this for the whole VM.
45   *
46   * @author Kohsuke Kawaguchi
47   */
48  public final class SchemaCache {
49  
50      private Schema schema;
51  
52      private final URL source;
53  
54      public SchemaCache(URL source) {
55          this.source = source;
56      }
57  
58      public ValidatorHandler newValidator() {
59          synchronized(this) {
60              if(schema==null) {
61                  try {
62                      // do not disable secure processing - these are well-known schemas
63                      SchemaFactory sf = XmlFactory.createSchemaFactory(XMLConstants.W3C_XML_SCHEMA_NS_URI, false);
64                      schema = allowExternalAccess(sf, "file", false).newSchema(source);
65                  } catch (SAXException e) {
66                      // we make sure that the schema is correct before we ship.
67                      throw new AssertionError(e);
68                  }
69              }
70          }
71  
72          ValidatorHandler handler = schema.newValidatorHandler();
73          return handler;
74      }
75  
76  }