1 /*
2 * Copyright (c) 2014, 2018, 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.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24 package jnlp.converter.parser.xml;
25
26 import javax.xml.parsers.ParserConfigurationException;
27 import javax.xml.parsers.SAXParser;
28 import javax.xml.parsers.SAXParserFactory;
29
30 import org.xml.sax.InputSource;
31 import org.xml.sax.Attributes;
32 import org.xml.sax.SAXException;
33 import org.xml.sax.helpers.DefaultHandler;
34
35 import java.io.StringReader;
36 import java.io.IOException;
37 import java.util.Stack;
38
39 public class XMLParser extends DefaultHandler {
40
41 private XMLNode _root;
42 private final String _source;
43 private Stack<XMLNode> _inProgress;
44 private String _characters;
45
46 // although defined in com.sun.org.apache.xerces.internal.impl.Constants,
47 // we should not be able to access that, so defined here
48 private final static String DTD_DOWNLOAD =
49 "http://apache.org/xml/features/nonvalidating/load-external-dtd";
50
51 private static final SAXParserFactory SPF = SAXParserFactory.newInstance();
52
53 /*
54 * Construct an <code>XMLParser</code>.
55 *
56 * @param source - the source text to parse.
57 */
58 public XMLParser(String source) {
59 _source = source.trim();
60 }
61
62 public XMLNode parse() throws SAXException {
63 // normally we parse without validating, but leave option to parse
64 // with validation, possibly controlled by config option.
65 return parse(false);
66 }
67
68 public XMLNode parse(boolean validating) throws SAXException {
69 _root = null;
70 _inProgress = new Stack<>();
71
72 try {
73 InputSource is = new InputSource(new StringReader(_source));
74 SPF.setValidating(validating);
75 // only download dtd file from DOCTYPE if we are doing validation
76 try {
77 SPF.setFeature(DTD_DOWNLOAD, validating);
78 } catch (Exception e) {
79 }
80 SAXParser sp = SPF.newSAXParser();
81 sp.parse(is, this);
82 } catch (ParserConfigurationException | IOException pce) {
83 throw new SAXException(pce);
84 }
85
86 return _root;
87 }
88
89 @Override
90 public void startElement(String uri, String localeName, String qName,
91 Attributes attributes) throws SAXException {
92
93 XMLAttribute first = null;
94 XMLAttribute last = null;
95 int len = attributes.getLength();
96
97 for (int i = 0; i < len; i++) {
98 XMLAttribute att = new XMLAttribute(
99 // in old implementation attribute names and values were trimmed
100 attributes.getQName(i).trim(), attributes.getValue(i).trim());
101 if (first == null) {
102 first = att;
103 }
104 if (last != null) {
105 last.setNext(att);
106 }
107 last = att;
108 }
109 _inProgress.push(new XMLNode(qName, first));
110 _characters = null;
111 }
112
113 @Override
114 public void endElement(String uri, String localeName, String elementName)
115 throws SAXException {
116 XMLNode node = _inProgress.pop();
117 // <information>
118 // <title>Title</title>
119 // <vendor>Vendor</vendor> "Some whitespaces"
120 // </information>
121 // In example above when we receive end of <information> we will
122 // have _characters set to whitespace and new line and it will be
123 // added as child node to <information>. This will break our cache code
124 // which will think that JNLP file changed on server even if it is not
125 // and thus we might not load properly.
126 //
127 // <application-desc name="HelloWorld" main-class="HelloWorld">
128 // <argument> test with whitespaces </argument>
129 // </application-desc>
130 // From example above we want to include whitespaces for <argument>.
131 //
132 // <node1>
133 // <node2>abc</node2>
134 // xyz (might be whitespaces)
135 // </node1>
136 // In JNLP spec we do not have cases when node have nested nodes as
137 // well as text which is whitespaces only.
138 //
139 // So to fix it lets check if ending node have nested nodes, then do
140 // not add whitespaces only node.
141 if (node != null && node.getNested() != null && _characters != null) {
142 String trimCharacters = _characters.trim();
143 if ((trimCharacters == null) || (trimCharacters.length() == 0)) {
144 _characters = null; // No need to add whitespaces only
145 }
146 }
147 if ((_characters != null) && (_characters.trim().length() > 0)) {
148 addChild(node, new XMLNode(_characters));
149 }
150
151 if (_inProgress.isEmpty()) {
152 _root = node;
153 } else {
154 addChild(_inProgress.peek(), node);
155 }
156 _characters = null;
157 }
158
159 @Override
160 public void ignorableWhitespace(char[] chars, int start, int length)
161 throws SAXException {
162 String s = new String(chars, start, length);
163 _characters = ((_characters == null) ? s : _characters + s);
164 }
165
166 private void addChild(XMLNode parent, XMLNode child) {
167 child.setParent(parent);
168
169 XMLNode sibling = parent.getNested();
170 if (sibling == null) {
171 parent.setNested(child); // set us as only child
172 } else {
173 while (sibling.getNext() != null) {
174 sibling = sibling.getNext();
175 }
176 sibling.setNext(child); // sets us as youngest child
177 }
178 }
179 }