1 /**
2 * This file Copyright (c) 2017-2018 Magnolia International
3 * Ltd. (http://www.magnolia-cms.com). All rights reserved.
4 *
5 *
6 * This file is dual-licensed under both the Magnolia
7 * Network Agreement and the GNU General Public License.
8 * You may elect to use one or the other of these licenses.
9 *
10 * This file is distributed in the hope that it will be
11 * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
12 * implied warranty of MERCHANTABILITY or FITNESS FOR A
13 * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
14 * Redistribution, except as permitted by whichever of the GPL
15 * or MNA you select, is prohibited.
16 *
17 * 1. For the GPL license (GPL), you can redistribute and/or
18 * modify this file under the terms of the GNU General
19 * Public License, Version 3, as published by the Free Software
20 * Foundation. You should have received a copy of the GNU
21 * General Public License, Version 3 along with this program;
22 * if not, write to the Free Software Foundation, Inc., 51
23 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
24 *
25 * 2. For the Magnolia Network Agreement (MNA), this file
26 * and the accompanying materials are made available under the
27 * terms of the MNA which accompanies this distribution, and
28 * is available at http://www.magnolia-cms.com/mna.html
29 *
30 * Any modifications to this file must keep this entire header
31 * intact.
32 *
33 */
34 package info.magnolia.importexport.filters;
35
36 import static com.google.common.collect.Sets.newHashSet;
37
38 import java.util.Set;
39
40 import org.xml.sax.Attributes;
41 import org.xml.sax.SAXException;
42 import org.xml.sax.helpers.AttributesImpl;
43 import org.xml.sax.helpers.XMLFilterImpl;
44
45 /**
46 * This filter allows skipping "unwanted" name spaces, by giving an explicit white-list of allowed namespaces.
47 *
48 * <p>This is particularly useful for JCR exports, as we don't want to pollute bootstrap files,
49 * which could in turn pollute the namespace registries of other instances, or cause conflicts there.<br>
50 * Magnolia's JCR export typically white-lists only <code>sv</code> and <code>xsi</code> namespaces.
51 *
52 * @see <a href="https://jira.magnolia-cms.com/browse/MAGNOLIA-2960">MAGNOLIA-2960</a>
53 * @see <a href="https://jira.magnolia-cms.com/browse/MAGNOLIA-7022">MAGNOLIA-7022</a>
54 */
55 public class NamespaceFilter extends XMLFilterImpl {
56 private final Set<String> whitelistedNamespaces;
57
58 public NamespaceFilter(String... whitelistedNamespaces) {
59 this.whitelistedNamespaces = newHashSet(whitelistedNamespaces);
60 }
61
62 private boolean inSkippedNs;
63
64 @Override
65 public void startPrefixMapping(String prefix, String uri) throws SAXException {
66 if (whitelistedNamespaces.contains(prefix)) {
67 super.startPrefixMapping(prefix, uri);
68 } else {
69 inSkippedNs = true;
70 }
71 }
72
73 @Override
74 public void endPrefixMapping(String prefix) throws SAXException {
75 if (!inSkippedNs) {
76 super.endPrefixMapping(prefix);
77 }
78 inSkippedNs = false;
79 }
80
81 /**
82 * org.apache.jackrabbit.commons.xml.ToXmlContentHandler does not honour the prefix mapping
83 * thus exclusions need to be handled here.
84 */
85 @Override
86 public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
87 AttributesImpl filteredAttributes = new AttributesImpl();
88 for (int i = 0; i < attributes.getLength(); i++) {
89 String attUri = attributes.getURI(i);
90 String attLocalName = attributes.getLocalName(i);
91 if (!"http://www.w3.org/2000/xmlns/".equals(attUri) || whitelistedNamespaces.contains(attLocalName)) {
92 filteredAttributes.addAttribute(attUri, attLocalName, attributes.getQName(i), attributes.getType(i), attributes.getValue(i));
93 }
94 }
95 super.startElement(uri, localName, qName, filteredAttributes);
96 }
97 }